ICMR 2016

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ICMR 2016
International Conference on
Metals and Materials Research
(ICMR 2016)
June 20 - 22, 2016
Indian Institute of Science
Bangalore, India
Program and Abstracts
Metallurgy
Materials Engineering
Organised by
The Indian Institute of Metals, Bangalore Chapter
Metal Sciences Division, The Indian Institute of Metals
Electron Microscope Society of India
&
in Collaboration with
Department of Materials Engineering, IISc, Bangalore
Department of Metallurgical Engineering, IIT, BHU
T R Anantharaman Education and Research Foundation
National Institute for Advanced Studies, Bangalore
Indian National Science Academy
Preface
It gives us immense pleasure to bring out this Programme and Abstract Book for the International
Conference on Metals and Materials Research (ICMR2016) being held during June 20-22, 2016 at
the Indian Institute of Science, Bangalore. The primary organizers of the conference are The Indian
Institute of Metals (Bangalore Chapter and Metal Sciences Division) and the Electron Microscope
Society of India in collaboration with the Department of Materials Engineering, IISc. We were
overwhelmed by many other organizations joining this effort leading to Materials Alliance Partners.
The past two decades have witnessed extraordinary developments in the discovery of new metallic
structures and materials. Thanks to the demographic dividend that India enjoys a very large number
of students are entering metallurgical and materials research. The conference will bring together
leaders in the field with the young researchers.
The initial impulse for this conference comes from the students of Prof. S. Ranganathan on his
completing 75 years. He has been an inspiration and role model to many metallurgists and materials
scientists for the past 5 decades and continues to inspire everyone who comes in contact with him.
This conference is also intended to celebrate the growth of materials science in the past 5 decades in
the fields to which Prof. Ranganathan made seminal contributions.
ICMR 2016 preparations started with a rich Advisory Committee comprising of outstanding
scholars in the fields of metallurgical engineering and materials science. We are grateful to all of
them for their immense support, which has helped us to bring out a technically rich programme for
the conference. The conference starts with an Inaugural talk by Prof. C.N.R. Rao. There are 6
plenary talks and 67 invited oral presentations. In addition, 49 posters are being presented by senior
research scholars and young researchers.
.
We are grateful to all the participants who have come enthusiastically from long distances to
participate in this conference. We are also grateful to all those who agreed to Chair the technical
sessions. We are grateful to all the government and private sponsors for the conference, without
whose support it would not have been possible to organise it.
We are confident that this conference will be an enriching experience to every participant.
ICMR 2016 Advisory & Organising Committees
International Conference on Metals and Materials Research (ICMR 2016)
June 20-22, 2016
Indian Institute of Science, Bangalore, India
Programme Schedule
Day 1: 20th June 2016
08:30-09:30 Registration (Faculty Hall Reception Area)
Inauguration: 09:30-10:40: Faculty Hall
09:30-09:35 Welcome: T.A. Abinandanan, Chairman, Materials Eng., IISc, Bangalore
09:35-09:40 About ICMR-2016: V.S. Raja, Conference Chair, IIT Bombay
09:40-09:50 Inauguration & Presidential Address: Anurag Kumar, Director, IISc, Bangalore
09:50-10:35 Inaugural Talk:
2-D Inorganic Analogues of Graphene
C.N.R. Rao, JNCASR, Bangalore
10:35-10:40 Vote of Thanks: S. Subramanian, Past Chairman, IIM Bangalore Chapter
Tea & Group Photo: 10:40-11:30
11:30-13:00 Plenary Session – 1:Faculty Hall
Chair: I Manna, IIT Kanpur & Pradip Dutta, IISc, Bangalore
11.30-12:00 Optimizing the Mechanical Properties of Metallic Glasses
A.L. Greer, University of Cambridge, UK
12:00-12:30 Studying defects in the TEM
Barry Carter, University of Connecticut, USA
12:30-13.00 Pathways for developing high-temperature alloys: Knowledge, experimental tools,
and serendipity
K. Chattopadhyay, IISc, Bangalore
Lunch : 13:00-14:00
Parallel Technical Sessions: 14:00 – 15:40
Hall A: Materials Engineering Lecture Theatre
Session – 1 A
Alloy Design & Development - I
June 20, 2016 (Day - 1)
Time: 14:00 – 15:40
Chair: R. Krishnan, GTRE, Bangalore
14:00-14:25 History of Iron (and Steel) making in Sweden
S. Seetharaman, Royal Institute of Technology, Sweden
14:25-14:50 The transformation of steel in the last fifty years
Sanak Mishra, Indian Steel Association, New Delhi
14:50-15:15 Aluminium – Lithium (Al-Li) Alloys For Aerospace Applications
N. Eswara Prasad, DMSRDE, Kanpur
15:15-15:40 Futuristic Materials for Defence
Samir V. Kamat, DMRL, Hyderabad
Hall B: SSCU Auditorium
Session – 1 B
Computational Materials Science – I
June 20, 2016 (Day - 1)
Time: 14:00 – 15:40
Chair: B. Gurumoorthy, IISc Bangalore
14:00-14:25 Development of Approximate Gibbs Energy Functions based on Cluster Variation
Method
S. Lele, IIT BHU, Varanasi
14:25-14:50 TCS PREMΛP – A Platform for the Realization of Engineered Materials and
Products based on the State-of-the-Art Integrated Computational Materials
Engineering (ICME) Framework
1
Pradip, TCS, Pune
14:50-15:15 Physical Metallurgy in the ICME Era
G. Phanikumar, IIT Madras
15:15-15.40 Phase field modelling of anisotropic precipitate morphologies: some computer
experiments
M. Gururajan, IIT Bombay
Hall C: MRC Auditorium
Session – 1 C
Advanced Materials & Processing
June 20, 2016 (Day - 1)
Time: 14:00 – 15:40
Chair: A. M. Umarji, IISc, Bangalore
14:00-14:25 Pack Aluminizing of Austenitic Stainless Steels
V. A. Ravi, Cal Poly Pomona, USA
14:25-14:50 Emerging Trends in Processing of Advanced Metallic Materials
S. N. Ojha, IIT BHU
14:50-15:15 High Nitrogen Stainless Steels for Nuclear Industry
U. Kamachi Mudali, IGCAR, Kalpakkam
15:15-15.40 Development of Multifunctional Bioceramics and External Field Stimulated Cell
Functionality Modulation: A New Paradigm
Bikramjit Basu, IISc, Bangalore
Tea : 15:40-16:10
Parallel Technical Sessions: 16:10 – 17:25
Hall A: Materials Engineering Lecture Theatre
Session – 2 A
Alloy Design & Development – II
June 20, 2016 (Day - 1)
Time: 16:10 – 17:25
Chair: Dilshad Akhtar, DRDO, Delhi
16:10-16:35 Size Dependent Polymorphic Phase Transformation in Early Transition Metals
Induced by Mechanical Attrition/Milling
I. Manna, IIT Kanpur
16:35-17:00 Structural origin of industrial alloys
C. Dong, Dalian Univ. of Technology, China
17:00-17:25 Materials selection for extreme environments – using property correlations and
systematics
John Rodgers, Nanoholdings, USA
Hall B: SSCU Auditorium
Session – 2 B
Materials Design
June 20, 2016 (Day – 1)
Time: 16:10 – 17:25
Chair: O. N. Srivastava, BHU, Varanasi
16:10-16:35 Microstructural Property Relationships of Plasma Sprayed YttriaStabilised
Zirconia Coatings
Chris Berndt, Swinburne Univ. of Technology, Australia
16:35-17:00 Bulk and Surface Grain Boundary Engineering for Improved Resistance to
Corrosion and Stress Corrosion Cracking Resistance of Nuclear Alloys
Vijay Vasudevan, University of Cincinnati,USA
17:00-17:25 Corrosion degradation of materials in nuclear reactors and its control
Vivekanand Kain, BARC, Mumbai
19:00-22:00
Banquet at Hotel Le Meridien including Felicitation to Prof. Ranganathan
2
Day 2: 21st June 2016
Plenary Session – 2:Faculty Hall
Chair: Vikram Jayaram, IISc, Bangalore & K. Muraleedharan, CGCRI,
Kolkata
09:00-09:30 Development and Applications of Al- and Cu-based Metastable Metallic Alloys
A. Inoue, Tohoku University, Japan
09:30-10:00 Evolution of Microstructures in Laser Processed Grey Cast Iron
S. Banerjee, BARC, Mumbai
10:00-10:30 Interdisciplinary Measurements in a Spectrum of Applications Related to Frontier
Technologies
Baldev Raj, NIAS, Bangalore
Tea: 10:30-11:00
Parallel Technical Sessions: 11:00 – 12:40
Hall A: Materials Engineering Lecture Theatre
Session – 3 A
Phase Transformations – I
June 21, 2016 (Day - 2)
Time: 11:00 – 12:40
Chair: Giridhar Madras, IISc, Bangalore
11:00-11:25 In-situ tracking of defects and phase evolution in light alloys of magnesium and
aluminum
C. Ravindran, Ryerson University, Canada
11:25-11:50 An Integrated Approach for Understanding of Precipitate Morphologies and
Applications to Light Metals
Wenzheng Zhang, Tsinghua University, Beijing
11:50-12:15 Nanostructured Al-Fe-Cu quasicrystals and inverse Hall-Petch behavior
N. K. Mukhopadhyay, IIT BHU
12:15-12:40 Disorder trapping during solidification of nickel aluminides
R. Sankarasubramanian, DMRL, Hyderabad
Hall B: SSCU Auditorium
Session – 3 B
Computational Materials Science – II
June 21, 2016 (Day - 2)
Time: 11:00 – 12:40
Chair: Abhik Choudhury, IISc, Bangalore
11:00-11:25 Prediction of robust non-centrosymmetric topological Dirac semi-metallic state in
ternary half-Heusler compounds
Umesh Waghmare, JNCASR, Bangalore
11:25-11:50 Morphological instabilities in Cylindrical Pores
T. A. Abinandanan, IISc, Bangalore
11:50-12:15 Industrial Realization of Integrated Computational Materials Engineering (ICME)
Satyam Sahay, John Deere, Pune
12:15-12:40 Entropy and Entropic Stabilization of Alloy Phases
S. Raju, IGCAR, Kalpakkam
Hall C: MRC Auditorium
Session – 3 C
High Entropy Alloys
June 21, 2016 (Day - 2)
Time: 11:00 – 12:40
Chair: Om Prakash, Boeing International Corp., Bengaluru
11:00-11:25 Physical metallurgy of high-entropy alloys
J. W. Yeh, National Tsing Hua University, Taiwan
11:25-11:50 A combinatorial assessment of AlxCrCuFeNi2 (0<x<1.5) complex concentrated
alloys: microstructure, microhardness, and magnetic properties
Rajarshi Banerjee, University of North Texas, USA
11:50-12:15 Challenges in High Entropy Alloy Research
B. S. Murty, IIT Madras
09:00-10:30
3
12:15-12:40
Strength of Ultrafine-Grained High Entropy Alloys
N. Balasubramanian, Bangalore
Lunch : 12:40-14:00
Poster Session : Department of Materials Engineering: 14:00 – 15:30
Chair: Abhik Choudhury, IISc, Bangalore
Tea: 15.30 – 16.00
Hall B: SSCU Auditorium
Session – 4 B
Quasicrystals
June 21, 2016 (Day – 2)
Time: 16:00 – 16:50
Chair: T. A. Bhaskaran, NAL, Bangalore
16:00-16:25 Advance Characterization of Materials for High Temperature Applications
Partha Ghoshal, DMRL, Hyderabad
16:25-16:50 Effect of quasicrystalline phase on the microstructure and mechanical properties of
magnesium alloys
Alok Singh, NIMS, Japan
Hall C: MRC Auditorium
Session – 4 C
Phase Transformations - II
June 21, 2016 (Day – 2)
Time: 16:00 – 16:50
Chair: Kaushik Chatterjee, IISc, Bangalore
16:00-16:25 Refined microstructures in metastable beta titanium alloys – role of nonconventional transformation pathways
Hamish Fraser, Ohio State University, USA
16:25-16:50 Phase Transition and Anomalous Diffusion in Metastable β Ti-Mo
Srinivasan G. Srivilliputtur, North Texas, USA
18:00-20:00
20:00-22:00
Dance Programme by Ms. Shobana at JRD Tata Auditorium, National
Institute of Advanced Studies
Dinner at Green house, National Institute of Advanced Studies
Day 3: 22nd June 2016
Parallel Technical sessions: 09:00 – 10:30
Hall A: Materials Engineering Lecture Theatre
Session – 5 A
Materials Characterization
June 22, 2016 (Day - 3)
Time: 09:00 – 10:40
Chair: P. Shankar, Saveetha University, Chennai
09:00-09:25 Surface mechanical and structural characterization to understand domains of
tribology in automotive engines
Vikram Jayaram, IISc, Bangalore
09:25-09:50 Microstructural Evolution and Structure-Property Relationships of Mushy State
Rolled In-Situ Al-4.5Cu-5TiB2 Composite
Rahul Mitra, IIT Kharagpur
09:50-10.15 Nanoscale quantitative magnetic information and probing optical band gap by HREELS in an aberration corrected transmission electron microscope
Ranjan Datta, JNCASR, Bangalore
Hall B: SSCU Auditorium
Session – 5 B
Advanced Materials - II
June 22, 2016 (Day - 3)
Time: 09:00 – 10:40
Chair: C.G.K. Nair, SIATI, Bangalore & Rudra Pratap, IISc, Bangalore
09:00-09:25 Phase separation in Ce-Al (Ga) metallic glass
R. S. Tiwari, BHU, Varanasi
09:25-09:50 Self-Accommodation in Nanocrystalline NiTi Shape Memory Alloys
4
Gouthama, IIT Kanpur
09:50-10.15 Stabilization of coherent precipitates in nanoscale thin films
Anandh Subramaniam, IIT Kanpur
10:15-10:40 Understanding Solidification of Alloys through Study of Glass/crystal Composites
G. K. Dey, BARC, Mumbai
Hall C: MRC Auditorium
Session – 5 C
Computation and Materials Education
June 22, 2016 (Day - 3)
Time: 09:00 – 10:40
Chair: E. S. Raja Gopal, IISc, Bangalore
09:00-09:25 Toughness in metallic glasses
Shantanu Madge, NML, Jamshedpur
09:25-09:50 Miller-Bravais Indexing Scheme: Beyond Its Classical Form
R. K. Mandal, IIT BHU
09:50-10.15 Dislocations in Crystals: Some Interesting Facts and Models
Rajesh Prasad, IIT Delhi
10:15-10:40 Optical Dilatometer: A New way to Understand and Quantify Sintering Kinetics
of Iron Ore Pellets
N. N. Viswanathan, IIT Bombay
Tea : 10:40 – 11:10
Parallel Technical sessions: 11:10 – 12:50
Hall A: Materials Engineering Lecture Theatre
Session – 6 A
Materials Behavior
June 22, 2016 (Day - 3)
Time: 11:10 – 12:50
Chair: S. Gopalkrishnan, IISc, Bangalore
11:10-11:35 Orientation Sensitive deformation in Zr alloys: experimental and modeling studies
Dinesh Srivastava, BARC, Mumbai
11:35-12:00 Iron Age high-tin bronzes from Tamil Nadu and comparisons with southeast Asia
Sharada Srinivasan, NIAS, Bangalore
12:00-12:25 Advanced Materials Technologies for Structural Component Repair
Dheepa Srinivasan, GE, Bangalore
12:25-12:50 Solidification microstructure and temperature field during normal casting of Al3Fe alloy
Yu Fuxiao, North Eastern University, China
Hall B: SSCU Auditorium
Session – 6 B
Materials Processing
June 22, 2016 (Day - 3)
Time: 11:10 – 12:50
Chair: K.A. Natarajan, IISc, Bangalore
11:10-11:35 Oxygen Dissolved in Wrought Iron
Kazuhiro Nagata, Tokyo Institute of Technology, Japan
11:35-12:00 The Indigenous Hafnium Metal: A Journey from Crust to Space
S. C. Sharma, VSSC, Trivandrum
12:00-12:25 Microbially assisted processes in mineral processing, extractive metallurgy and
environmental remediation
S. Subramanian, IISc, Bangalore
12:25-12:50 Thermo-mechanical Simulation of Austenite Recrystallisation and Softening
during Hot Rolling of Line Pipe Steel
S. Manjini, JSW, Mumbai
Hall C: MRC Auditorium
Session – 6 C
Advanced Materials - III
June 22, 2016 (Day - 3)
Time: 11:10 – 12:50
Chair: N. S. Mishra, NIFFT, Ranchi & P. Ramesh Narayanan, VSSC, Trivandrum
11:10-11:35 Development of HSLA steels for Naval Applications
5
R. Balamuralikrishnan, DMRL, Hyderabad
11:35-12:00 The Quest For Hydrophobic Metal
M.S.M. Saifullah, Singapore
12:00-12:25 Biomedical Imaging Using Nanoparticles
Chandan Srivastava, IISc, Bangalore
12:25-12:50 Development of an aluminium alloy for aerospace applications at higher
temperatures
Subodh Kumar, IISc, Bangalore
Lunch : 12:50 - 14:00
Parallel Technical Sessions: 14:00 – 15:40
Hall A: Materials Engineering Lecture Theatre
Session – 7 A
Grain boundary Engineering
June 22, 2016 (Day - 3)
Time: 14:00 – 15:40
Chair: Jagadeesh Gopalan, IISc, Bangalore
14:00-14:25 Rendering aluminium alloy 7010 resistant to stress corrosion cracking through
engineering microstructures
V. S. Raja, IIT Bombay
14:25-14:50 Recent trends in grain boundary engineering
Satyam Suwas, IISc, Bangalore
14:50-15:15 Abnormal grain growth and mechanical behaviour of electrodeposited
nanocrystalline Ni and alloys
M.J.N.V. Prasad, IIT Bombay
15:15-15:40 Effect of crystallographic texture on twinning during cyclic loading: A case study
on stainless steel and commercially pure titanium
Nilesh Gurao, IIT Kanpur
Hall B: SSCU Auditorium
Session – 7 B
Advanced Materials - IV
June 22, 2016 (Day - 3)
Time: 14:00 – 15:40
Chair: Praveen C. Ramamurthy, IISc, Bangalore
14:00-14:25 Reactive spark plasma sintering process for synthesis of nanocrystalline ultra high
temperature ceramic based nanocomposites
Srinivasa Rao Bakshi, IIT Madras
14:25-14:50 Internal Hydrogen Embrittlement in Cr-Mn-N Austenitic Stainless Steels and a
High Entropy Alloy
M. Phaniraj, Seoul National University, South Korea
14:50-15:15 Phase Transformations in Al-based Quasicrystalline Intermetallics during
Mechanical Milling
T. P. Yadav, BHU, Varanasi
Hall C: MRC Auditorium
Session – 7C
Functional Materials
June 22, 2016 (Day - 3)
Time: 14:00 – 15:40
Chair: Rajeev Ranjan, IISc, Bangalore
14:00-14:25 Metallic glass composites for defence applications
Bhaskar Majumdar, DMRL, Hyderabad
14:25-14:50 Structural Origin of Electrochemical Activity in Transverse Compositionally
Graded Li(Ni, Mn)xOy Cathodes
Joysurya Basu, IIT BHU
14:50-15:15 Atomic scale study of Cu clustering and pseudo-homogeneous nanocrystallization
in Fe-Si based soft magnetic amorphous alloys
K. G. Pradeep, Germany
High Tea: 15.40 – 16.10
6
International Conference on Metals and Materials Research (ICMR 2016)
June 20-22, 2016
Indian Institute of Science, Bangalore, India
List of Posters
The following is the list of 49 posters to be presented at the conference. These are being presented
by senior PhD students from 14 institutions. The posters are arranged in the alphabetical order of
the Institutes. Within each institute the posters are arranged in the alphabetical order of the
presenting author.
1.
Nano Titanium dioxide Incorporated Phosphate Coatings on Low Carbon Steel for Corrosion
Protection
Pravin P. Deshpande and Vaibhav S. Kathavate
COEP, Pune
2. Study of Aging Induced Degradation of Fracture Resistance for Alloy 617
Aditya Narayan Singh, A. Moitra, P. Bhaskar, G. Sasikala, Arup Dasgupta, A. K. Bhaduri
and A. Moitra
IGCAR, Kalpakkam
3. Spinodal Decomposition and ω Transformation in Binary V-Ti and Ternary V-Ti-Cr Alloys
Chanchal Ghosh, Joysurya Basu, Divakar R and E Mohandas
IGCAR, Kalpakkam
4. Corrosion behavior of TiZrHfNbTa high entropy alloy in nitric acid containing halide ions
J. Jayaraj and U. Kamachi Mudali
IGCAR, Kalpakkam
5. Evolution of crystallographic texture and microstructure in sputter deposited NiMnGa thin
films and their influence on magnetic properties.
Amit Sharma, S. Mohan and Satyam Suwas
IISc, Bangalore
6. Long term thermal stability of a new solar selective absorber coating
Atasi Dan, Kamanio Chattopadhyay, Harish C. Barshilia and Bikramjit Basu
IISc, Bangalore
7. Isolation of pristine MXene from Nb4AlC3 MAX phase: A first-principles study
Avanish Mishra, Pooja Srivastava, Hiroshi Mizuseki, Kwang-Ryeol Lee and Abhishek K.
Singh
IISc, Bangalore
8. Development of wrought Mg-Li based alloys with improved strength and ductility
Chandra Shekhar Perugu, Subodh kumar and Satyam Suwas
IISc, Bangalore
9. Formation of amorphous phase by supressing the binary intermetallic compound with
equiatomic substitution
S. Kashyap and B. S. Murty
IISc, Bangalore
10. Grain boundary crystallography in polycrystalline yttria stabilized cubic zirconia with
varying densities and grain sizes
Maya K. Kini and Atul H. Chokshi
IISc, Bangalore
11. Fabrication and tuning the nanoporous channel in nanoporous membranes derived using
crystallization induced phase separation in polymeric blends
Maya Sharma, Giridhar Madras and Suryasarathi Bose
IISc, Bangalore
12. High temperature and high strength aluminium alloys by Dispersions of Al 9Ni2 intermetallic
compound
P. Padaikathan and K. Chattopadhyay
IISc, Bangalore
13. Tin Whisker Growth from Electro-deposited Sn films: Role of Crystallographic Texture,
Stress and Substrate
Piyush Jagtap
IISc, Bangalore
14. Shear Flow Induced Cellular Morphological And Functionality Changes In A Microfluidic
Device
Sharmistha Naskar, Bikramjit Basu and V. Kumaran
IISc, Bangalore
15. 3D powder printing of resorbable calcium phosphate scaffold for low load-bearing
application using novel phytic acid binder
Sourav Mandal, Susanne Christ, Uwe Gbureck and Bikramjit Basu
IISc, Bangalore
16. Three Dimensional Inkjet Powder Printing of Ti-6Al-4V based Scaffolds with Homogeneous
and Gradient Porosity
Srimanta Barui, Alok Kumar, Sourav Mandal and Bikramjit Basu
IISc, Bangalore
17. Intriguing aspects of growth, structure and properties of molecular-scale Au nanowires
Subhajit Kundu and N. Ravishankar
IISc, Bangalore
18. Phase transformation and biocompatibility study of metastable β Ti-Nb-Sn alloy
for orthopedic applications
Sumit Bahl, Satyam Suwas and Kaushik Chatterjee
IISc, Bangalore
19. Phase-field study of the electric current induced void evolution and grain-boundary grooving
Supriyo Chakraborty and Abhik Choudhury
IISc, Bangalore
20. Multi-phase flow model of a blast furnace
SmitaKamble, Vinci Mojamdar and Govind S. Gupta
IISc, Bangalore
21. Phase Transformations in Al-based Quasicrystalline Intermetallics during Mechanical
Milling Processing and Characterization of AlCoCrFeNi and AlCoCrFeNiMn High entropy
alloys (HEAs) via Mechanical Alloying
Vikas Shivam and N. K. Mukhopadhyay
IIT BHU, Varanasi
22. Microstructure and Mechanical properties of Sn reinforced Al–Cu–Fe quasicrystalline matrix
composite
Yagnesh Shadangi, Kausik Chattopadhyay and N. K. Mukhopadhyay
IIT BHU, Varanasi
23. Application of secondary aging for rising environmentally assisted cracking resistance of AA
7010
M. Ajay Krishnan and V. S. Raja
IIT Bombay
24. Hydrogen evolution on magnesium during anodic polarization: A consequence of enrichment
of noble alloying elements
Poorwa Gore, Nick Birbilis and V. S. Raja
IIT Bombay
25. Green Synthesis and Stability of Pristine Free Standing Silver Metal Nanoparticles by
Cryomilling
Nirmal Kumar and Krishanu Biswas
IIT Kanpur
26. Bulk Preparation of Graphene: Synthesis and Application
Shikhar Misra and Krishanu Biswas
IIT Kanpur
27. New insights for modeling strain hardening behaviour in age hardenable Al alloys
Sumeet Mishra, ManasijYadava, Kaustubh Kulkarni and N. P. Gurao
IIT Kanpur
28. Microstructure, mechanical and oxidation properties of Ti-Al-Ni-Cr-Co-Fe based multicomponent alloys
R. Anand Sekhar, Niraj Nayan, G. Phanikumar and Srinivasa R. Bakshi
IIT Madras
29. Implication of grain boundary engineering on high temperature hot corrosion of alloy 617
K. Deepak, Sumantra Mandal, C. N. Athreya, Dong-Ik Kim, B. de Boer and
V. Subramanya Sarma
IIT Madras
30. Phase Prediction Studies in AlCoCrFeNi High Entropy Alloy
Guruvidyathri K, Ravikirana, Mayur Vaidya, Hari Kumar K. C and B. S. Murty
IIT Madras
31. Phase evolution in nanocrystalline AlCoCrFeNi by varying sequence of elemental additions:
Novel approach to alloy synthesis using mechanical alloying
Mayur Vaidya, Anil Prasad, Abhinav Parakh and B. S. Murty
IIT Madras
32. Sol-gel synthesis of yttrium monosilicate
Raghunandan Subbarao, M. Kamaraj and Ashutosh S. Gandhi
IIT Madras
33. Effect of Deformation Temperature on Tensile and Fracture properties of Al 2014 alloy
processed through Multidirectional Forging
Amit Joshi, K. K. Yogesha, Nikhil Kumar and R. Jayaganthan
IIT Roorkee
34. Effect of annealing on the improvement of mechanical properties of low stacking fault
energy Cu-Al alloys processed by cryorolling
Dasharath S M and Suhrit Mula
IIT Roorkee
35. Electrophoretic Coating of Nanostructured Hydroxyapatite on Mg-3Zn Alloy for
Orthopaedic Application
Manoj Kumar R, Kishor Kumar Kuntal, Sanjay Singh, Pallavi Gupta, Bharat Bhushan, P.
Gopinath and Debrupa Lahiri
IIT Roorkee
36. Effect of Grain refinement on Mechanical behavior of Mg-2Gd-2Zn Processed through
Multiaxial Forging and Rolling
Raviraj Verma, R. Jayaganthan, S. K. Nath and A. Srinivasan
IIT Roorkee
37. Predicting the stability of an HEA: a first-principles analysis
Meha Bhogra, Umesh V. Waghmare and S. Ranganathan
JNCASR, Bangalore
38. Nanoscale quantitative magnetic information by EMCD and HREELS
D. S. Negi, B. Louky and R. Datta
JNCASR, Bangalore
39. Novel Refractory High-Entropy Alloys MoxNbTiVxZr(x = 0.3, 0.5, 0.75, and 1.0)
Ko-Kai Tseng and Jien-Wei Yeh
National Tsing Hua University, Taiwan
40. Microstructural evolution of In-situ Al-Mg2Si composites
Prosanta Biswas, Manas Kumar Mondal and Durbadal Mandal
NIT Durgapur
41. Phase field Study of Static Recrystallization and Phase Transformation during intercritical
annealing of dual phase steels
Ayush Suhane, Akash Bhattacharjee and Gerald Tennyson
TRDDC, Pune
42. Mathematical Modelling of Grain Growth during Reheating
Himanshu Nirgudkar, Saurabh Mangal, Savya Sachi and Gerald Tennyson
TRDDC, Pune
43. Multiscale Modelling of Deformation Behavior
Srimannarayana Pusuluri, Danish Khan, Arshdeep Singh, Pramod Zagade and B. P.
Gautham
TRDDC, Pune
44. Indentation Response of Microcrystalline and Nanocrystalline Ti-Ni-Cr-Co-Fe High Entropy
Alloy
Abhijit, G. M. Reddy and Koteswara Rao V. Rajulapati
Univ. of Hyderabad, Hyderabad
45. Strain hardening and flow properties of Nimonic C-263 alloy at different strain rates and
temperatures
Jhansi Jadav, Koteswara Rao V. Rajulapati, N. Eswara Prasad and K. Bhanu Sankara Rao
Univ. of Hyderabad, Hyderabad
46. Influence of Parent Metal Microstructure on the Creep Behaviour of Ti6Al4V Friction Welds
Rahul, K. V. Rajulapati, G. M. Reddy, T. Mohandas and K. Bhanu Sankara Rao
Univ. of Hyderabad, Hyderabad
47. Superplastic behaviour of a new variant of AA 5456 alloy
J. Varghese, K. A. Padmanabhan, K. S. Suresh and D.V.V. Satyanarayana
Univ. of Hyderabad, Hyderabad
48. An atomic cluster model to understand localized deformation behavior in metallic glass
K.S.N. Satish Idury, B. S. Murty and Jatin Bhatt
VNIT, Nagpur
49. Effect of Varying Soaking Period during Cryogenic Treatment of Cubic Boron Nitride
(CBN) Cutting Inserts
Swamini Chopra, S. A. Pande, K. N. Pande , D. R. Peshwe and V. G. Sargade
VNIT, Nagpur
Abstract of Inaugural Talk
1
Inorganic graphene analogues
C.N.R. Rao
International Centre for Materials Science and
Jawaharlal Nehru Centre for Advanced Scientific Research
Bangalore 560 064, India
E-mail: [email protected]
Graphene has been a sensational discovery of recent years. In the last two to three years, there has
been effort to prepare graphene-like layered inorganic materials such as MoS2, WS2, GaS and BN.
Several methods of synthesis of such nanosheets have been developed [1,2].Some of the recent
results on few-layer metal chalcogenides and BN will be presented. Especially interesting are the
physical properties of these nanomaterials such as magnetism and superconductivity [3]. Transistors
and devices have been fabricated with many of the few-layered inorganic materials [2,3]. A new
graphene-like material is BxCyNz with high surface area and novel gas adsorptive properties. These
materials have other extraordinary properties, their use as electrocatalysts being especially
noteworthy [4].
1. C.N.R. Rao, H.S.S.R. Matte and U. Maitra, Angew Chem. Int. Ed. 52, 13162 (2013).
2. C.N.R. Rao, U. Maitra and U.V. Waghmare, Chem. Phys. Lett. (Frontiers article) 609, 172
(2014).
3. C.N.R. Rao, K. Gopalakrishnan and U. Maitra, ACS Appl. Mater. Interfaces (spot light) 7, 7809
(2015).
4. M. Chhetri, S. Maitra, H. Chakraborty, U.V. Waghmare and C.N.R. Rao, Energy & Environ. Sci.
9, 95 (2016).
2
Abstracts of Plenary Talks
3
Optimizing the mechanical properties of metallic glasses
A. Lindsay Greer
University of Cambridge, Department of Materials Science & Metallurgy,
27 Charles Babbage Road, Cambridge CB3 0FS, UK
E-mail: [email protected]
While the exceptionally high yield stress and elastic strain limit of metallic glasses could make
them attractive for applications, there is a problem with their lack of tensile ductility. The worksoftening and strain localization (shear-banding) that are characteristic of metallic glasses allow
substantial toughness, and plasticity in bending, but plasticity in tension is essentially zero. One
approach to alleviating this problem is to incorporate the metallic glass as one component of a
composite; in this way useful property compromises can be achieved. Our focus will instead be on
what can be achieved by modifying the structure of single-phase monolithic metallic glasses.
Annealing metallic glasses induces structural relaxation, generally degrading the mechanical
properties, and ultimately leading to severe embrittlement. There is therefore interest in reversing
this relaxation or ageing; this has been termed rejuvenation. Possible ways of achieving
rejuvenation are reviewed. It is shown that property improvements can be achieved, and that these
may even include some tensile ductility. Plastic deformation is one way to achieve rejuvenation.
Indeed, metallic glasses are ideally suited for exploration of the effects of deformation on the
structure and properties of glasses in general. It is expected that plastic deformation can change the
structure and properties, but is more surprising that there can be very significant effects even well
within the (nominally) elastic regime. In this talk we explore the extent to which higher-energy
„rejuvenated‟ states can be achieved (and retained) in metallic glasses. It turns out that a metallic
glass of a given composition can show an exceptionally wide range of enthalpy (and entropy), much
wider than can typically be achieved in crystalline states. We also explore the extent to which
directionality (anisotropy) can be induced in metallic glasses. In each case, we examine the
potential applications of the properties that can be induced.
Keywords: Metallic glass; Elasticity; Plastic deformation; Thermal expansion; Anisotropy.
Studying defects in the TEM
C. Barry Carter
Department of Chemical & Biomolecular Eng. and
Department of Materials Science & Eng.
191 Auditorium Road, Storrs, CT 06269 USA
E-mail: [email protected]
One of the first applications of the transmission electron microscope was to study defects in
different materials. Such studies were quickly extended to examine how different defects interact,
and thus to understand work hardening, precipitation and precipitation hardening, radiation damage,
etc. An early challenge concerned how to record all the data that the operator of the TEM observed
while operating the TEM, which quite quickly led to early video techniques. Video recording has
now become standard but methods for handling so much data are still in their infancy. Many
phenomena were examined that unfortunately required better image resolution and precision than
was actually available, which prompted Feynman‟s famous, though initially little appreciated,
comment on the need for improvements in resolution. Fortunately, the TEM has improved as
nanotechnology and the need to understand in nanomaterials has grown. I will examine the current
state of our understanding of crystal lattice defects using different techniques in the TEM, and will
4
consider some of the areas of current research. In particular, I will discuss where we are in
understanding the core structure of dislocations as an example of using improvements in resolution
and precision. Regarding the latter, I will mainly pay attention to FCC and BCC metals but will also
consider how resolution is impacting our understanding of defects in other crystal systems. I will
discuss defect processes occurring during lithiation as an example of using operando and video
techniques in the TEM, and consider the future of 4D studies of these defect processes. While
discussing these experimental programs, I will emphasize that computation is not a substitute for
experimental observation; it is a guide to interpretation and a means for extending our
understanding of physical processes, but must be subject to experimental verification and should
never be a substitute for experiment.
Keywords: Crystal Defects; TEM; Dislocations; Defect Interactions; Interfaces.
Pathways for developing high-temperature alloys:
Knowledge, experimental tools, and serendipity
K. Chattopadhyay
Department of Materials Engineering
Indian Institute of Science, Bangalore
E-mail: [email protected]
The quest for developing newer materials has moved into multiple paths depending on the
requirements of the society and fancy and imagination of the time. Currently, the most popular
route to developing new materials is through scaling down the length scale, the so-called
nanomaterials. However, increasingly society is looking at materials that can withstand harsh
environment that includes high temperature, ability to withstand high strain rate and tolerance to
damage under difficult environmental conditions. There is no doubt that newer metallic alloys and
ceramics are going to play a leading role in this endeavour. In the last five years, our group is
increasingly exploring newer alloys that may meet some of these future demands.
Many of our efforts flow from our realisation that ordered structure and complex chemistry and
microstructure are key to achieving some of these goals. The recent interests in complex alloys like
high entropy materials and ICMS are a harbinger to a new direction in materials development.
However, the importance of serendipity that flows from knowledge and creative out of box thinking
may play the most crucial role.
We shall touch upon in this talk some of the critical issues in developing such materials and
presentsome exciting high-temperature alloy development programme in our group. These include a
nickel-based complex intermetallic ternary eutectics for possible high-temperatureapplication and a
new class of high-temperature Cobalt based superalloys that can rival nickel-based superalloys. We
shall also touch upon our effort to develop new processing pathways that have the possibility to
yield aluminium alloys that can be deployed at temperatures beyond 250oC, a high-temperature
alloy in the aluminium parlance.
5
Development and applications of Al- and Cu-based
metastable metallic alloys
A. Inoue1,2,3, F.L. Kong2, S.L. Zhu1 and Al. Marzouki3
1
School of Materials Science and Engineering, Tianjin Univ., Tianjin, China
2
International Institute of Green Materials, Josai International Univ., Togane 283-8555, Japan
3
Department of Physics, King Abdulaziz Univ., Jeddah 22254, Saudi Arabia
E-mail: [email protected]
For the last several decades, we have been developing nonequilibrium metallic engineering
materials including bulk glassy alloys and bulk nanocrystalline alloys in various alloy systems by
effective combination of appropriate alloy components, unique preparation techniques and optimum
preparation conditions. The multiplication of alloy components gives a variety of opportunities to
develop novel engineering metallic materials with useful functional properties, resulting in the
establishment of a new material science field as multicomponent alloy science and technology.
Among these nonequilibriummetallic materials, Fe-, Al- and Cu-based alloys aremost important
alloy groups because of their abundant natural resources, easy production and treatment, non-toxic
and low material cost, in addition to their useful engineering characteristics which can be obtained
only in specially designed metastable structure states. We have succeeded in commercializing these
metastable materials in Fe-, Al- and Cu-based alloy systems for the last several decades to date. The
application production amounts are much larger for Fe-based metastable alloys and hence their
application examples have already been introduced in other conferences and symposiums. It is here
valuable to focus on the development history, unique structures, properties and application
examples of Al- and Cu- based metastable alloys in this conference. By optimizing ally composition
and production process and condition, their alloys can have various nonequilibrium phases such as
amorphous, glassy, nanocrystalline, nanocomposite, quasicrystalline and nanoquasicrystalline
phases. The production methods are extended in a variety range of rapid solidification (melt
spinning and atomization), vapor deposition, copper mold casting, warm consolidation, hot
pressing, mechanical grinding, cold drawing and cold stamping etc. The Al-based metastable alloys
exhibit high specific strength, high specific heat resistant strength, high elevated fatigue strength,
high corrosion resistance, high wear resistance, low coefficient of thermal expansion etc. which
exceed significantly those for conventional Al-based alloys, while Cu-based metastable alloys
exhibit high mechanical strength, high ductility, high electrical conductivity, high thermal
conductivity in sheet and wire forms and high catalytic and electrode properties in various chemical
reactions in nanopowder and nanoporous forms. By utilizing these characteristics, Al- and Cu-based
metastable alloys have been used as engineering materials in the past and present times. This paper
aims to present the development history, structural features, fundamental properties, engineering
characteristics, application examples and future prospect of the Al- and Cu- based metastable alloys
developed by our group.
6
Evolution of microstructures in laser processedgrey cast iron
Srikumar Banerjee
Bhabha Atomic Research Centre
Trombay, Mumbai 400 085
E-mail: [email protected]
The laser glazing treatment results in the formation of two distinct layers - fusion and heat affected
zones - on the surface of grey cast iron samples. The observed thicknesses of these layers could be
predicted with reasonable accuracies from the thermal history computed from the inputs of the
energy density and the interaction time of the incident laser beam. Micro-structural observations in
different length scales have shown that the fusion zone is characterised by the complete dissolution
of graphite flakes and the formation of dendrites of super-saturated austenite. During the subsequent
rapid cooling process, the latter undergoes solid state phase transformations in various nonequilibrium routes. The heat affected zone corresponds to the region where the pearlite matrix
transforms into austenite without any significant dissolution of graphite flakes during the heating
operation. The transformation processes in the austenite during cooling are controlled by the extent
of carbon super-saturation and the cooling rate prevailing in the local region. The transformation
paths in different regions are rationalised in terms of the thermodynamics and kinetics of the
competing processes.
Interdisciplinary measurements in a spectrum of applications related to frontier
technologies
Baldev Raj
National Institute of Advanced Studies
Indian Institute of Science Campus, Bangalore 560 012
E-mail: [email protected]
Measurements are fascinating and valuable pursuits made visible by Galileo Faraday, Michelson,
etc. Galileo inspires to do relevant well designed measurements to get insights of phenomena and
mechanisms. The judicious choice of measurements in technology is based on usefulness, time
required for measurements, cost and effectiveness in correlations with relevant properties and
performance criteria. A single measurement technique and methodology is rarely adequate for the
purpose and thus multi-measurement techniques and correlations through breaking the silos of
techniques and disciplines is practiced for challenging problems posed to experts for solutions.
Science, innovation and laboratory measurements with correlations pursued by the author in
electromagnetic and acoustic domains are described with illustrative examples. In the laboratory,
non-destructive measurements research problems were chosen based on commitment to enhance
sensitivity, selectivity and establishing correlations. The sensors and equipment developed by the
author, signal analysis and imaging approaches, and new correlations are the focus of the
presentation. Author highlights but does not restrict the presentation to research works in advanced
steels and zirconium based alloys for nuclear energy.
Microstructures (grain size, texture, precipitates, etc.) defects (dislocation cracks, etc.) and residual
stresses were characterized and measured to enable high value performance assessments. The
author gained expertise for solutions through collaboration with experts in design, manufacturing,
mechanics and mechanical metallurgy, physical metallurgy, corrosion, science and technology, endusers and regulatory bodies, etc.
7
Science and approaches so developed have been applied to nuclear reactors, nuclear recycle plants,
fighter aircrafts, space launch vehicles, submarines, missiles, fossil power plants, chemical
industry, manufacturing industry engaged in high precision components, medical diagnosis,
cultural objects and heritage monuments, etc. The success is attributed to interdisciplinary
motivated teams. The expertise was designed to intermix and grow in multiple schools and
organizations for enabling competence in the country and also generating human resources, at all
levels. Quality of results, sufficiency of expertise and competence have resulted in
eminentcollaborations worldwide and recognitions at national and international levels for the
author, colleagues and collaborators. The explorations cover dimensions of a few Angstrom to 25
meters (>1010) and time periods of (>1018) scales. This fascinating journey of the author owes
indebtedness in an un-measurable way to Prof. S Ranganathan, as the author learnt art and rigour of
„exploring the unexplored‟ from Prof. S Ranganathan.
8
Abstracts of Invited Oral Presentations
9
History of iron (and steel) making in Sweden
Seshadri Seetharaman1 and Yngve Axelsson2
1
Royal Institute of Technology, Vallslingan 14, SE-187 52 Täby, Sweden
2
Yngve Axelsson, Swedish Steel Producers Association, SE-111 47 Stockholm
E-mail: [email protected]
Sweden, despite being one of the small countries in Europe, is a major steel producer today. The
Swedish steel manufacturers specialize on “niche” products and are world leaders in a number of
areas as for example, Sandvik in seamless tubes, Uddeholm in tool steel, OVAKO (SKF) in ballbearing steels, Swedish Steel Co (SSAB) in high strength steel and Höganäs in iron powder..
Evidences of iron production in Sweden can be traced to nearly 2000 B.C. The proximity to
continental Europe, led to a gradual transfer of iron making technology. Iron slag from bronzeage
had been excavated in Sweden. During the period when the Vikings ruled in Scandinavia, the art of
sword-making developed well.
The modern Swedish iron and steel making era started during the middle ages. The blast furnace
technology was started in Sweden during the 12th century and was improved by Germans and
Walloons (the latter from today‟s Belgium). In the period between 1800 and 1910, the Swedish iron
production went up to 700 000 tons. The Swedish steelmakers were keenly aware of the evolution
of new technologies. Already in 1862, Göran Fredrik Göransson bought parts the patent by
Bessemer on the new concept for steelmaking and installed the process in Högbo steel plant a
forerunner to Sandvik steel today. In 1860, the open hearth process was installed in Munkfors.
During early 1900s, Sweden was well-advanced with regard to the understanding of the
fundamentals of steelmaking and development of newer steel technologies. Professor Wiberg
(Royal Institute of Technology) came up with the Wiberg process and Professor Kalling (also from
the Royal Institute of Technology), the Kaldo process. Currently, when iron and steel making
scenario in the world is dominated by China, Sweden is still holding the leading position with
constant research support by Swedish Steel Producers Association.
Keywords: Sweden, ironmaking, steelmaking, history, Jernkontoret
The transformation of steel in the last fifty years
B. K. Jha1, Ramen Datta1 and Sanak Mishra2
1
R & D Centre for Iron & Steel, SAIL, IspatBhawan, Doranda, Ranchi-834002
2
8A, Hansalaya Building, 15, Barakhamba Road, New Delhi 110001
E-mail: [email protected]
Steel is an important material for the development of modern economy and is considered the
backbone of human civilization. Iron and Steel, by virtue of low cost, versatility and recyclability
find use in multifaceted applications ranging from safety pins to smart cars to high-tech computers
and satellites. Steel production is, therefore, treated as an important socio-economic development
indicator, reflecting the economic growth potential of the country. While the annual world steel
production has increased four-fold in the last fifty years from ~460 MT in 1965 to ~1665 MT
presently, the Indian Steel industry has grown at a much faster rate from ~6.3 MT to ~86.5 MT in
the corresponding period. Concurrent with increased consumption of steel, the steelmaking and
processing technology have undergone dramatic changes in the last fifty years to meet the needs
10
and expectations of the market and society. This is attested by the fact that ~75% of the steels in use
today did not exist 30 years earlier.
The steelmaking process and performance capabilities of steel products have undergone significant
improvements in the last five decades. The open hearth furnaces and Bessemer converters in use in
the 60‟s and 70‟s have been replaced by basic oxygen furnaces (BOF) and electric arc furnaces
(EAF) for steelmaking. The size of these converters increased over time from 20-30 tons to 300
tons. With a thrust to produce high quality clean steel, remarkable advances were made in the
efficiency of de-phosphorization and de-sulfurization, and high-speed degassing (VAD, VD, RH
etc.)
Rapid introduction of continuous casting in the 70‟s has been one of the major technological breakthrough in the last 50 years. It has led to substantial improvements in terms of yield, energy, cost
and quality of cast product, as opposed to traditional ingot casting. Further developments of thin
slab and near net shape casting in the 90‟s has extended process continuity upto the hot rolled strip
stage. The long term challenge of integrating the steelmaking and rolling process was finally
realized with the development of the compact strip production (CSP) process.
The introduction of micro-alloying and thermo-mechanical controlled processing (TMCP) has
revolutionized the art of steel processing. This has made possible the production of high strength
lightweight structures by way of increasing the strength/weight ratio. For example, in 1958, 4200
tons of steel was used for constructing the 333m tall Tokyo Tower using 235 MPa mild steel.
Today, the same structure can be built using half the amount of material using >400 MPa microalloyed steel. Recent research efforts are directed towards the production of transformation
strengthened steels having a complex micro-structure of ferrite-bainite-martensite and exhibiting
high strength levels alongwith superior low temperature impact toughness and ductile to brittle
transition temperature (DBTT).
Speaking of the Indian scenario, advancements in steelmaking and processing have culminated in
the development of a wide variety of special steels for various market segments including
automobile, defence, railways, linepipes, pressure vessels, power, mining, heavy machinery etc.
The first micro-alloyed steel in the country was made at Rourkela Steel Plant in the end 70‟s and
rolled into plates. The plates found application in the construction of the BOF Shop at Bhilai Steel
Plant. Various grades of micro-alloyed steels under the brand name SAILMA was developed
subsequently, with SAILMA-600 being the latest addition. In addition to SAILMA, API grade
plates and hot strips of X-60 / X-65 / X-70 grades were developed for the transportation of oil and
natural gas. An innovative concept of using silicon in presence of niobium was used for
development of a series of high strength formable quality (HSFQ) hot rolled grades having
YS:350/450/500/550 MPa for commercial vehicles, earthmovers, etc. Another major work in recent
times relates to development of high strength LPG steel for lighter domestic cylinders made from
2.45mm thick HR coils in place of conventional 2.9mm HR coils. Development of high strength
rails with superior low temperature fracture toughness and corrosion resistant rails for coastal
regions, higher grades of CRNO steels for electrical appliances, soft iron plates for magnetic
detector for Indian Neutrino Observatory (INO) and seismic resistant TMT reinforcement bars for
the earthquake prone zones are some major initiatives taken at RDCIS and SAIL plant units. To
meet the strategic requirements of the country, a wide variety of Q&T grades of high strength plates
have been developed such as SPADE for battle tanks, JACKAL for bullet proof vehicles, SAIL
KAVACH for bullet proof vests, DMR 249 Gr.A&B for warships and DMR 292 Gr.A for
submarines.
Keywords: Steelmaking, continuous casting, thermo-mechanical controlled processing, phase
transformation, product development
11
Aluminium – lithium (Al-Li) alloys for aerospace applications
Eswara Prasad Namburi
Defence Materials& Stores R&D Establishment (DMSRDE),
GT Road, Kanpur – 208 013, India
E-mail: [email protected]; [email protected]
In the aerospace industry it is essential that materials with a low density and high strength-toweight ratio are employed. This is why the latest (3rd) generation of aluminium - lithium (Al-Li)
alloys are strong candidates for widespread structural applications. Judicious combinations of
alloying elements, together with Li contents kept below 2 wt.% and innovative processing
techniques have resulted in a range of alloys offering substantial weight savings and improvements
in mechanical properties such as strength, fatigue, fracture toughness and SCC resistance.
The present talk summaries the development and limitations of the 1st and 2nd generation Al-Li
alloys, and then discusses the recent developments leading to the 3rd generation alloys. Emphasis
will be placed on obtaining improved property combinations via various microstructural
modifications that are closely linked to multi-stage processing. Finally, the way forward for Indian
Development of 3rd generation Al-Li alloys will be briefly considered.
Keywords: Al-Li Alloys; 1st, 2nd and 3rd Generations; Microstructure; Properties; Applications.
Futuristic materials for defence
Samir V. Kamat
Defence Metallurgical Research Laboratory, Hyderabad 500058
E-mail: [email protected]
Materials such as metals, alloys, ceramics and glass have been used by mankind for millennia. In
fact, materials have shaped not only warfare but entire civilizations. They have been considered of
such importance that historians and other scholars have named certain ancient periods after the
material which was predominantly utilized at that respective time. In recent times, the field of
materials science has shown tremendous expansion and this trend is expected to continue and even
accelerate in the future.
From the perspective of materials for defence; weapon systems and platforms in the future will have
common requirements for advanced materials that will enable significant changes in:
maneuverability (mobility, speed, agility); force protection (from nuclear, biological, chemical,
kinetic, or explosive weapons through stealth, identification, armour, and active defence);
engagement (highly concentrated and sustained firepower); and logistics (durability,
maintainability). Advances in materials are the fundamental enablers to meet these needs. Futuristic
materials will be required to satisfy diverse requirements in terms of speed, strength, precision,
survivability, signature, materials selection, cost, weight, and commonality. Materials will have to
endure tougher environments for longer periods of time-from ocean depths to extreme cold to desert
heat to space reentry. New material development cycle from discovery to induction will also have to
be much faster than what it is today. In the present talk some of these issues will be discussed.
Keywords: Defence, Futuristic Materials
12
Development of approximate Gibbs energy functionsbased on
cluster variation method
Shrikant Lele, B. Nageswara Sarma and Rajendra Prasad Gorrey
Department of Metallurgical Engineering,
Indian Institute of Technology (Banaras Hindu University), Varanasi-221005
E-mail: [email protected]
The cluster expansion and cluster variation methods (CE-CVM) respectively provide the most
accurate analytical formulations for configurational enthalpy and entropy of solution phases. These
methods describe short range order (SRO) in terms of microscopic state variables called correlation
functions (CFs), which need to be determined by solving a transcendental system of equilibrium
equations for each of the choices of temperature and composition of the phase concerned. The
algebraic complexity and computational burden involved in these methods are thus of very high
order, especially for multicomponent systems as well as ordered phasesand have severely limited
the application of these methods in computational thermodynamics.
A systematic procedure for obtaining approximate Gibbs energy expressions (G) which are based
on CE-CVM is outlined. In the first step, theequilibrium CFsis expressed in terms of certain
anchoring functions which account for their temperature dependence at a few chosen compositions.
In the second step, the CFs is expressed as interpolating polynomials in terms of composition by
utilizing these anchoring functions. These approximating polynomials are substituted in the G
functional of CE-CVM.The Gexpression thus obtained corresponds to the equilibrium state of the
phase concerned. Thus, this procedure eliminates the requirement of solving the transcendental
system of equilibrium equations and considerably reduces the computational burden, making it
comparable to the standard Calphad methods, without losing the description of SRO.
Keywords: Computational Thermodynamics, Cluster Variation Method, Calphad.
TCS PREMΛP – A platform for the realization of engineered materials and
products based on the state-of-the-art integrated computational materials
engineering (ICME) framework
B.P. Gautham, Amarendra K Singh, Sreedhar Reddy and Pradip
Tata Research Development and Design Centre
A Division of Tata Consultancy Services Ltd, 54B, Hadapsar Industrial Estate, Pune 411013
E-mail: [email protected]
It is now universally acknowledged that the way we design, develop and deploy engineering
products will undergo a rapid digital transformation in the near future. One of the key enablers of
this transformation is the advent of an integrated computational materials engineering (ICME)
framework which leverages the recent advances in high performance computing (HPC), data
sciences and digital technologies in general and our enhanced understanding of the underlying
science of materials design and manufacturing processes and utilizes the easy availability of a wide
variety of modeling-simulation tools. As envisaged in the 2008 NRC report on ICME, this novel
paradigm encompasses “the integration of personnel (e.g. engineers, designers etc.),
computational models, experiments, design and manufacturing processes across the product
development cycle, for the purpose of accelerating and reducing the cost of development of a
materials system or manufacturing process”. Such a broad based integration requires in addition to
13
modeling and simulation tools and methodologies, a versatile integration and collaboration IT
platform. TCS has developed a platform to address this need.
The transformative potential of our platform, TCS PREMΛP, in reducing the time, cost and the
effort needed to produce novel materials and products on an industrial scale, is illustrated in this
presentation with a proof-of-concept case study aimed at addressing the engineering scale-up
(robust design and decision support) issues related to the production of a new advanced high
strength steel (AHSS) grade, meeting key performance specifications of the steel sheet thus
produced in a plant obviating the need for many expensive plant trials. We demonstrate how our
platform can assist plant engineers to predict the mechanical properties of a steel sheet based on a
combination of continuum scale thermal and deformation models, studies on microstructural
evolution using phase field and crystal plasticity based methods for the prediction of microstructure
and RVE level investigations – all simulations carried out in the virtual environment.
Keeping in mind the current and the emerging needs of the materials community (both industry as
well as researchers), we have developed TCS PREMΛP as a generic platform which is highly
configurable, easy to use and enables ICME based design and development of materials and
products with facilities for integrated workflows for simulation, knowledge engineering support and
provision for integrating tools for optimization & design, handling uncertainty and complexity. The
platform supports formal decision support systems for design and development of engineered
products. Our platform further envisages incorporation of state-of-the art knowledge engineering
capabilities and tools to capture (and reuse) expertise in different domains and making it available
online to those users who are not necessarily well-versed in that particular domain, with the help of
our automated context-sensitive search and retrieval framework.
Physical metallurgy in the ICME era
Gandham Phanikumar
Department of Metallurgical & Materials Engineering
Indian Institute of Technology Madras, Chennai 600036, India
E-mail: [email protected]
In the recent years, the increase in high speed computational resources being available at affordable
costs and the need for reduction in the cycle time for development of engineered products have
driven the paradigm of Integrated Computation in Materials Engineering to take shape across the
world. The number of software tools, sophisticated characterization equipment and possibilities of
high throughput experiments available today are making this idea a feasible one. This also presents
a possibility to open up materials education as a more hands-on experience for the young students.
In my talk I will highlight the ongoing work at IIT Madras in this direction. The challenges and
opportunities for the metallurgical community in the pursuit of physical metallurgy in this paradigm
will also be presented.
14
Phase field modelling of anisotropic precipitate morphologies:
Some computer experiments
M. Gururajan
Department of Metallurgical Engineering and Materials Science,
Indian Institute of Technology Bombay, India
E-mail: [email protected]
Crystalline materials are anisotropic. Hence, during solid-solid precipitation, several anisotropies
influence the morphology of the precipitates. The origin of some of the anisotropies is energetic
(such as anisotropy of elastic and interfacial energies) while that of some others is kinetic (such as
anisotropy in attachment kinetics). In this presentation, we will describe the mathematical
formulation and numerical implementation of a family of phase field models to incorporate the
interfacial energy and attachment kinetics anisotropies and their effect on the morphologies of
precipitates during solid-solid transformations. Our models are capable of producing hexagonal and
some unusual cubic an isotropies in interfacial energies and are mathematically rigorous though
very involved in terms of numerical implementation. Finally, we will also indicate some problems
where incorporation of such anisotropies is crucial to understand the growth morphologies of
precipitates.
Pack aluminizing of austenitic stainless steels
Vilupanur A. Ravi
Department of Chemical and Materials Engineering, Cal Poly Pomona,
Pomona, CA 91768, USA
E-mail: [email protected]
Surface modification of austenitic stainless steels to obtain improved resistance against high
temperature environments would allow for higher operating efficiencies. Several approaches can be
deployed to achieve surface modification; however, the method chosen has to take into account
many factors including economics and design requirements. Halide activated pack cementation is a
versatile and economical approach to apply coatings of desired compositions to a range of
substrates, typically nickel and iron-based alloys. The coating process can be controlled to obtain
the desired final composition and microstructure. The in situ generation of halide vapor species
inside the pack with subsequent transport, surface reactions and solid state diffusion are all
important phenomena that play a crucial role in achieving optimal coating conditions. The effect of
pack composition, particularly the chemistry of the activator was investigated in the aluminizing of
UNS S30400 over a range of temperatures. In addition, different types of austenitic stainless steel
were also investigated under given processing conditions to study the effect of substrate
composition and austenite stability. The current status of the research will be discussed.
Keywords: Aluminide; pack cementation; austenite; stainless steels; coatings
15
Emerging trends in processing of advanced metallic materials
S. N. Ojha
Department of Metallurgical Engineering,
Indian Institute of Technology (BHU), Varanasi-221005
E-mail: [email protected]
Metals and alloys are invariably processed from liquid phase followed by their secondary
processing. The mechanical and physical properties of the alloys considerably depend on the initial
cast microstructure generated during solidification of the melt. The microstructure evolution during
normal freezing of the melt under various growth rate conditions is discussed. A transition from
planar to cellular to dendritic growth morphology and their consequent effect on macrosegregation
is analysed. The role of thermosolutal convection under various growth rate conditions during such
transition is described. The present analysis is extended to the case of non-equilibrium solidification
of the melt arising from large undercooling of the melt and high heat exchange rate. This effect is
examined in context with spray deposition processing of the melt. Adeviation in growth
morphology of phases and consequent microstructural changes in such processes is critically
compared. The effect of droplets dynamics and their thermal state on the deposition surface is
analysed. The process variables employed during melt atomization on droplets distribution in the
spray are shown to influence the solidification structure of the spray-deposits. The mechanisms
governing evolution of solidification structure, resulting morphology of the primary phase and
degree of macrosegregation are discussed and compared with those arising from normal freezing.
The methodology used to modify the cast structure to facilitate their secondary processing are
described. The mechanical and tribological properties of some of the monolithic Al-alloys and their
composites, synthesised by these techniques, are presented and discussed.
High nitrogen stainless steels for nuclear industry
U. Kamachi Mudali
Corrosion Science and Technology Group,
Indira Gandhi Centre for Atomic Research, Kalpakkam - 603 102, India
E-mail: [email protected]
Nitrogen alloying in stainless steels (SS) has myriad beneficial effects, including solid solution
strengthening, precipitation effects, phase control and corrosion resistance. Recent years have seen
a rapid development of these alloys with improved properties owing to advances in processing
technologies. Furthermore, unlimited demands for high-performanceadvanced steels for special use
in advanced applications renewed the interest in high nitrogen steels (HNS). The combination of
numbers of attractive properties such as strength, fracture toughness, wear resistance, workability,
magnetic properties and corrosion resistance of HNS has given a unique advantage and offers a
number of prospective applications in different industries. Based on extensive studies carried out at
IGCAR, nitrogen alloyed type 304LN SS and 316LN SS have been chosen as materials of
construction for many engineering components of fast breeder reactor (FBR) and associated
reprocessing plants. HNS austenitic SS alloys are used as structural/reactor components, i.e., main
vessel, inner vessel, control plug, intermediate heat exchanger and main sodium piping for fast
breeder reactor. HNS type 304LN SS is a candidate material for continuous dissolver, nuclear waste
storage tanks, pipings, etc. for nitric acid service under highly corrosive conditions. Recent
developments towards the manufacturing and properties of HNS alloys for application in nuclear
industry are highlighted in the presentation.
16
Development of multifunctional bioceramics and external field stimulated cell
functionality modulation: A new paradigm
Bikramjit Basu
Laboratory for Biomaterials, Materials Research Center/Center for Biosystems Science
and Engineering, Indian Institute of Science, Bangalore, India.
E-mail: [email protected]
One of the important innovations in the field of ceramics in last two decades has been the
development of bioceramics for the replacement and regeneration of the human tissues. This talk
will first introduce the important milestones achieved in the development of various classes of
bioceramics (bioactive, bioinert and bioresorbable). Some of the landmark developments include
the surface functionalization of ceramic particles for drug delivery, the use of rapid prototyping
techniques (laser-engineered net shaping, three dimensional printing etc.) to develop patientspecific implants, the multifunctional bioceramics and novel approaches for biocompatibility
enhancement. In view of the similarity with the natural bone composition, Calcium phosphate
(CaP)-based bioceramics attracted wider attention.
In this perspective, this talk will cover the development of calcium phosphate-based multifunctional
composites for hard tissue regeneration. In particular, the challenges in designing the synthetic
ceramics to mimic bone-like strength / fracture toughness and electrical or piezoelectric properties
will be emphasized. Importantly, it will be addressed as how to tailor the substrate properties to
facilitate better bone cell proliferation or cell differentiation both in the presence or absence of
external electric field stimulation. Specifically, it will be shown how the intermittent delivery of
pulse electric field stimulation (1-2 V/cm) can enhance cell growth on electroconductive bioceramic
substrates, which are fabricated using a novel processing scheme (multi-stage Spark Plasma
Sintering). The effectiveness of the above approach will be demonstrated using multiple cell lines
(bone cells, neuronal cells, muscle cells) as well as on some model systems with varying stiffness
and conductivity properties. This novel approach overcomes the conventional biological approach
of various biochemical growth factor additions to enhance cell growth/differentiation in
vitro.Extending the approach of electrical stimulation, subsequent research has demonstrated the
synergy of the external magnetic field and magnetization of biomaterial substrates in suppressing
bacterial colonization, leading to inhibition of prosthetic infection. The recent results obtained with
a model system, HA-Fe3O4 will be presented to address this issue.
Size dependent polymorphic phase transformation in
early transition metals induced by mechanical attrition/milling
Indranil Manna
Indian Institute of Technology, Kanpur
E-mail: [email protected]
Metall. & Mater. Engg. Dept., I. I. T., Kharagpur 721 302, India
E-mail: [email protected]
Mechanical milling/attrition of elemental powder leads to significant grain refinement through a
process of repeated cold welding, fragmentation and dynamic recrystallization. The milling
products are often metastable or non-equilibrium in nature like glassy/amorphous, quasicrystalline,
etc. We have earlier reported that several early transition metals (Nb, Ti, Zr) undergo a metastable
bcc/hcp  fcc polymorphic/allotropic transition in the course of planetary ball milling [1-6].
17
Recently, Liu et al [7] have reported a similar severe plastic deformation (via high energy shot
peeing) induced hcp fcc phase transition in bulk Ti-6Al-4V alloy and observed twinning in fcc
grains as a means to accommodate plastic deformation in nanocrystalline state. Thus, hcp fcc
phase transition is now proven in bulk alloys besides the earlier reported occurrence of such
changes only in thin films and mechanically milled powders. In the present talk, I intend to review
salient features of this bcc/hcp fcc polymorphic transformation in early transition metals with
some interesting results from Ti-Zr binary alloys [8].
Crystal/microstructural changes associated with this transformation were monitored by X-ray
diffraction and high-resolution transmission electron microscopy. In addition, careful chemical
analysis was conducted to assess the role of both substantial/interstitial impurities in such
transformation. Electrical resistivity measurements suggest that the milling products are metallic
and not intermetallic or ceramic. Furthermore, nanocrystallization seems a prerequisite for
structural instability that propels this change in crystal structure. The transformation remains
incomplete unless the total strain and strain rate are adequate. The phase change is gradual and
accompanied by a finite increase in volume per atom. Finally, it is suggested that structural
instability due to negative (from core to boundary) hydrostatic pressure arising out of
nanocrystallization or grain refinement, increasing lattice expansion and plastic strain/strain-rate is
responsible for this bcc/hcp  fcc polymorphic transformation in early transition metals.
References:
1. Phys. Lett. A 328 (2004) 246-254.
3. Appl. Phys. Lett. 81 (2002) 4136-4138.
5. Mater. Sci. Eng. A304-306 (2001) 424-428.
7. Scripta Mater. 119 (2016) 5-8.
2.
4.
6.
8.
J. Appl. Phys. 93 (2003) 1520–1524.
Phys. Rev. B63 (2001) 54107–113.
J. Appl. Phys. 86 (1999) 5912–5914.
Mater. Sci. Eng. A417 (2006) 110-113.
Structural origin of industrial alloys
Chuang Dong
Key Laboratory for Materials Modification by Laser, Ion and Electron Beam
(Dalian University of Technology), Ministry of Education, Dalian 116024, China
E-mail: [email protected]
Industrial alloys are all based on solid solutions. It has been long accepted that materials
performance is largely dominated by short-range-ordering in solid solutions. Since alloys have
specific chemical compositions, certain chemical building blocks should be present, on which the
compositions reside. For the objective of obtaining such composition blocks, the cluster-plus-glueatom model will be introduced, which regards any structure as being composed of a nearestneighbor polyhedral cluster part and an outer-neighbor glue atom part situating between the
clusters, expressed with universal cluster formulas [cluster](glue atom)x. Averaged chemical
building blocks can be defined, mimicking molecules for chemical substances. Such local units
provide the key clue towards understanding the seemingly complicated composition rules of all
kinds of industrial alloys, such as low-E Ti and Zr alloys, stainless steels, high strength and
conductive Cu alloys, Ni-based superalloys, and high-entropy alloys.
Keywords: Materials design; alloys; cluster plus glue atom model.
18
Materials selection for extreme environments
using property correlations and systematics
John Rodgers
Nanoholdings LLC, 112 Rowayton Avenue, Rowayton, CT 06853
E-mail: [email protected]
An important research activity for materials used in military vehicles, operating in extreme
environments, is to identify those materials that are strong and stiff in extremes of temperature,
pressure, wear, erosive and corrosive environments. In the search for such materials the applications
of basic physical property considerations have been employed to locate the most promising
candidates. This presentation focuses on intermetallic compounds and ceramic coatings. Simple
physical properties will be employed to identify materials, by applying mathematical methods such
as correlations, systematics and estimations. The focus on intermetallic compounds is that their
stiffness is usually greater than the metallic elements from which they are formed and they maintain
their strength with increasing temperatures. For ceramic coatings such as nitrides, carbides and
borides of group IVB transition metals because of their hardness and their resistance to erosion and
wear. Materials informatics approaches combining quantum mechanical calculations, computational
combinatorial methods have been employed to calculate elastic tensors and to generate other
derived properties. These computationally derived results have been filtered using processing
insensitive properties, such as Tm and ρ to identify suitable candidate compounds. The methods
employed and their results will be presented.
Keywords: intermetallics, ceramics, properties, informatics.
Microstructural property relationships of plasma sprayed
yttria stabilised zirconia coatings
Christopher C. Berndt1 and Mitchell L. Sesso2
1
Swinburne University of Technology, Faculty of Science, Engineering and Technology
John Street, Hawthorn, 3122 Australia
2
The University of Melbourne, Chemical and Biomolecular Engineering,
Melbourne School of Engineering
E-mail: [email protected]
Thermal barrier coatings produced by plasma spraying yttria stabilised zirconia are commonly
applied to hot section components in gas turbine engines. These thermally insulating coatings
protect underlying components from hot combustion gasses, thereby allowing operating
temperatures to be increased. This leads to improved engine efficiency and extended operational
life. However, it has proved difficult to apply consistently high quality coatings to the complex freeform shaped turbine blades that are required in modern gas turbine engines.
Coating quality is determined by the microstructural properties and more importantly uniformity of
the coating microstructure. Aspects of this can be controlled by adjusting plasma spray process
parameters, but individual in-flight particle characteristics and trajectories cannot be altered to
conform to a complex shaped substrate. For this reason, there is a particular problem applying
coatings to parts that contain geometric features smaller than the spray footprint. The consistency
and quality of the coatings in these areas is limited by our current understanding of plasma spray
physics.
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In this presentation we develop an improved physical model for plasma spraying of sharp features
that would guide the optimization of the plasma spray process and lead to coatings of enhanced
consistency, quality and durability, and consequently reducing the costs for defense and commercial
air fleets.
Keywords: Thermal spray, Fractal roughness, root-mean square roughness, complex geometry,
microstructural properties
Bulk and surface grain boundary engineering for improved resistance to
corrosion and stress corrosion cracking resistance of nuclear alloys
Abhishek Telang1, Amrinder S. Gill2, Mukul Kumar3, Sebastien Teysseyre4, Dong Qian5,
S. R. Mannava1 and Vijay K. Vasudevan1
1
Department of Mechanical and Materials Engineering, University of Cincinnati,
Cincinnati, OH, USA 45221-0072
2
AK Steel, Research Center, 705 Curtis Street, Middletown, OH, USA
3
Lawrence Livermore National Laboratory, Livermore, CA, USA
4
Idaho National Laboratory, Idaho Falls, ID, USA
5
The University of Texas at Dallas, Richardson, TX, USA
E-mail: [email protected]
The effects of grain boundary engineering (GBE), utilizing bulk thermomechanical processing with
iterative cycles of 10% cold work and strain annealing, as well as a novel surface GBE method
(SGBE) involving ultrasonic nanocrystal surface modification plus strain annealing to modify the
near-surface microstructure (~250 m), on corrosion and stress corrosion cracking (SCC) behavior
of alloy 600 (Ni-15Cr-9Fe) was studied. The associated microstructural and cracking mechanisms
were elucidated using transmission (TEM) and scanning electron microscopy (SEM), coupled with
precession electron diffraction (PED) and electron back scatter diffraction (EBSD) mapping. Such
bulk and surface processing resulted in increased fraction of special grain boundaries and triple
junctions whilst decreasing the connectivity of random high angle grain boundaries. A disrupted
random grain boundary network and large fraction of coincident site lattice (CSL) boundaries (Σ3Σ27) reduced the propensity to sensitization, i.e. carbide precipitation and depletion of Cr at grain
boundaries. This GBE/SGBE Alloy 600 also showed higher intergranular corrosion resistance.
Slow strain rate tests in tetrathionate solution at room temperature show GBE lowered susceptibility
to intergranular SCC. The improvements with SGBE were comparable to those from bulk GBE. To
better understand the improvements in corrosion and SCC resistance, EBSD of regions around
cracks was used to analyze the interactions between cracks and various types of grain boundaries
and triple junctions. Detailed analysis showed that cracks were arrested at J1(1-CSL) and J2 (2CSL) type of triple junctions. The probability for crack arrest at special boundaries and triple
junctions, calculated using percolative models, was found to have increased after GBE, which also
explains the increase in resistance to corrosion and SCC in grain boundary engineered Alloy 600. A
clear correlation and mechanistic understanding relating grain boundary character, sensitization,
carbide precipitation and susceptibility to corrosion and stress corrosion cracking was established.
Keywords: Grain Boundary Engineering, Nuclear Alloys, Corrosion, SCC, EBSD, TEM, PED
20
Corrosion degradation of materials in nuclear reactors and its control
Vivekanand Kain
Head, Materials Processing & Corrosion Engineering Division
Bhabha Atomic Research Centre, Mumbai 400085, India
E-mail: [email protected]
As in every industry, nuclear industry also faces the challenge of corrosion degradation due to the
exposure of the materials to the working environment. The aggressiveness of the environment is
enhanced by the presence of radiation and high temperature and high-pressure environment.
Radiation has influence on both the materials (changes in microstructure and microchemistry) and
the aqueous environment (radiolysis producing oxidizing conditions). A survey of all the light water
reactors in the world showed that stress corrosion cracking (SCC) and flow accelerated corrosion
(FAC) account for more than two third of all the corrosion degradation cases. This paper visits these
two forms of corrosion in nuclear power plants and illustrates cases from Indian nuclear power
plants. Remedial measures against these two forms of corrosion that are possible to be employed
and the actual measures employed in Indian nuclear power plants are discussed. Key features of
SCC in different types of nuclear power plants are discussed. Main reasons for irradiation assisted
stress corrosion cracking (IASCC) are presented and discussed. The signature patterns of single and
dual phase FAC captured from components replaced from Indian nuclear power plants are
presented. The development of a correlation between the scallop size and rate of single phase FAC
– based on the database developed in Indian nuclear power plants is presented. Based on these two
forms of degradation in nuclear reactors, design of materials that would resist these forms of
degradation is presented.
In-situ tracking of defects and phase evolution in
light alloys of magnesium and aluminum
Ravi Ravindran1, Anthony Lombardi1, Eli Vandersluis1 and Dimitry Sediako2
1
Mechanical and Industrial Engineering, Ryerson University,
Toronto, Canada M5B 2K3
2
Canadian Neutron Beam Centre, Chalk River Laboratories,
Chalk River, Canada K0J 1J0l
E-mail: [email protected]
The development and application of low density alloys, such as Al and Mg alloys, has rapidly
increased in the automotive sector in recent years. This necessitates advanced characterization
techniques to assess features of the alloy during component manufacturing. For many Al and Mg
alloys, challenges (e.g. hot tearing, dimensional distortion) arise in casting and processing.
Understanding the mechanism of evolution of these defects is important in ensuring their
minimization. Neutron diffraction has provided a method to determine the factors that trigger hot
tearing in Al and Mg alloys. Neutron diffraction analysis is effectively used in determining factors
compromising integrity of powertrain components (e.g. engine blocks, cylinder heads). In addition,
neutron diffraction has been applied to examine the phase evolution during solidification of Al and
Mg alloys. This novel approach enabled better understanding of solidification characteristics with
inoculants and solute additions, resulting in improved castability. This presentation will highlight
the frontiers of neutron diffraction analysis in light alloy castings that was carried out at the Centre
for Near-net-shape Processing of Materials, Ryerson University and the Canadian Neutron Beam
Centre.
Keywords: light alloys, phase evolution, defects, neutron diffraction.
21
An integrated approach for understanding of precipitate morphologies and
applications to light metals
Wenzhang Zhang
School of Materials Science and Engineering
Tsinghua University, Beijing, 100084, China
E-mail: [email protected]
Precipitates in various metallic materials often display self-resemble morphologies. Facets with
reproducible crystallographic orientations are key a feature to understand the morphology. Facets in
irrational orientations appear puzzling since they disagree with one‟s expectation in accord with
facets in a crystal surface. Various models have been proposed to interpret the observed facets in
irrational orientations. An integrated approach that incorporates useful concepts of different models
will be described in this presentation. Singularity in the interfacial structure is addressed as the
signature of a singular interface, which is a candidate for a facet in real an interface. This general
approach is applicable to study a faceted interface no matter whether it has a rational or irrational
orientation, and whether the primitive unit cells of two phases have similar sizes or remarkably
different sizes. Examples of precipitates in light metals, especially Ti and Mg alloys, will be used to
demonstrate the applications of this approach to systems consisting of either phases with simple
structures or phases with complicated structures.
Keywords: Morphology; Facetted interfaces; Orientation relationship; O-lattice; Singular interfaces
Nanostructured Al-Fe-Cu quasicrystals and inverse Hall-Petch behavior
N. K. Mukhopadhyay
Department of Metallurgical Engineering,
Indian Institute of Technology (Banaras Hindu University),
Varanasi 221 005, India
E-mail: [email protected]
Hall-Petch (HP) relationship correlating grain size with the mechanical properties is well
established in the metallic alloys and composite materials. The yield strength, σy, increases due to
the lowering of grain sizes. This is attributed to the dislocation strengthening and grain boundary
strengthening. After the discovery of nanograined materials, it appears that there may be a threshold
grain size below which the materials do not get hardened rather it gets softened. There is a need to
experimentally establish and to understand this behavior through indentation and other small
specimen testing techniques through the micro-mechanisms in the nano scale regime.
The present work is aimed at establishing the nature of Hall-Petch behavior in the
nanoquasicrystalline materials by investigating the indentation responses of the nano
quasicrystalline materials using high energy ball milling techniques. We have successfully
synthesized the nanoquasicrystalline materials by controlled high energy ball milling. The
nanograined quasicrystalline particles are collected after different milling timings avoiding any
phase transformations. Suitable processing for specimen preparation are carried out after embedding
the particles in polymer matrix. The polished surfaces of the particles are indented at a very low
load at the microindentation as well as nanoindentation techniques. The indentation hardness data is
plotted against the milling timings/ grain sizes. The Hall-Petch behavior was observed up to grain
size of 40 nm and below which the inverse Hall-Petch behavior was established. The indentation
data was analyzed using the models based on (i) dislocation pile-up, (ii) thermally activated grain
22
boundary sliding and (iii) mesocopic grain boundary sliding models. The relative merits and
demerits of each models will be discussed during presentation.
Keywords: Nanostructured materials, Quasicrystals, Al-Fe-Cu alloys, Inverse Hall-Petch
relationship
Disorder trapping during solidification of nickel aluminides
R. Sankarasubramanian and R. Ramakrishnan
Defence Metallurgical Research Laboratory,
Hyderabad – 500058, India
E-mail: [email protected]
Nickel aluminides, in their ordered form such as B2-NiAl and L12-Ni3Al have limited ductility and
disordering is one of the ways of enhancing their ductility. The extent of disorder can be controlled
by altering the solidification kinetics. In this work, molecular dynamics simulations have been
employed to study the effect of undercooling on the evolution of disorder in NiAl and Ni 3Al. The
initial configuration is a long rod consisting of nearly equal proportions of the ordered solid and the
liquid of appropriate composition. The solid-liquid interface is kept normal to the axis of the rod.
The two phase structure is undercooled to different temperatures and the solidified structures are
analyzed using suitable order parameters, to reveal the state of structural and chemical orders. The
solidification front velocities are calculated by tracking the interface using the structural order
parameter as a function of time. While the kinetics of solidification of the (nearly) ordered
structures is very sluggish, that of the disordered structures is fast and comparable to that of pure
metals. The extent of disorder is found to be more at larger undercoolings or faster interface
velocities. As the solidification of the ordered structure is diffusion-limited as opposed to the
collision-limited kinetics of the disordered structure, the anisotropic dependence of the interface
motion is also different for these structures.
Keywords: nickel aluminides, solidification kinetics, molecular dynamics, order parameter
Prediction of robust non-centrosymmetric topological Dirac semi-metallic state
in ternary half-Heusler compounds
Koushik Pal and Umesh V Waghmare
Chemistry and Physics of Materials Unit and Theoretical Sciences Unit,
Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore
560064 India
E-mail: [email protected]
Website: http://www.jncasr.ac.in/waghmare
Theoretical analysis of topological character of the quantum structure of electrons in a crystal and
prediction of their exotic transport, magnetic, chiral and superconducting properties have led to
profuse research in the last decade, and discovery of topological insulators, Weyl and Dirac semimetals. A Topological Dirac semi-metal (TDSM), a 3-dimensional analogue of graphene, is
particularly interesting as a parent to other topological states. While many materials have been
predicted to be topological Dirac Semi-metals, they are often centrosymmetric and not easy to
make. Here, we present a generic topological phase diagram of a large family of half-Heusler
compounds with strained structures maintaining a three-fold symmetry, and discover their highly
23
robust non-centrosymmetric TDSM state. Using an existing half-Heusler LiMgBi as a model
system in first-principles theoretical analysis, we show that isotropic compression stabilizes a
normal insulating state with ionic character, while axial compression along a three-fold symmetry
axis stabilizes the TDSM state. Secondly, symmetry of its valence and conduction bands permits a
gap-preserving transition with axial tension from its normal to topological insulating state. Showing
how insulators can arise from only metallic constituents and uncovering many half-Heuslers
exhibiting Dirac semi-metallic and other topological states, our work opens up tremendous
possibilities of their epitaxial hetero-structures and interfaces that involve chirality, polarity,
topology and correlations.
Keywords: Electronic Topology, Phase Transition, Topological Dirac Semi-metal, Topological
Insulator, Novel metals.
Morphological instabilities in cylindrical pores
Chaitanya Joshi and T. A. Abinandanan
Department of Materials Engineering
Indian Institute of Science, Bangalore 560 012, India
E-mail: [email protected]
We consider the onset of instabilities and their evolution in long cylindrical pores in thin solid films
/ membranes. We have studied two mechanisms: Rayleigh instability (RI) in single crystal films,
and grain boundary grooving (GBG) in polycrystalline films and we have used a phase field model
that takes into account atomic transport through surface diffusion. Under RI, surface perturbations
create constrictions and bulges in the pore; those perturbations with a wavelength of about 9 times
the pore radius (R) grow in amplitude (which is in agreement with theoretical predictions on the
wavelength of the fastest growing perturbation), eventually leading to pore closure at multiple
locations, and leaving behind spherical pores separated by about (9R). The time to the first closure
event scales with R4. GBG aids the development of pore constrictions; however, these constrictions
can lead to pore closure only if the grain size exceeds a threshold value (which, for a system with a
dihedral angle of 40 degrees, has been determined to be about 4 times the pore radius). Thus, pore
stability is higher in systems with lower grain boundary mobility. We will present the salient
features of our model, and discuss these main results and their implications to the stability of
films/membranes with continuous pores.
Industrial realization of integrated computational materials engineering (ICME)
Satyam S. Sahay
John Deere Technology Center India, Tower 14,
Magarpatta City, Pune 411013
E-mail: [email protected]
ICME framework is envisaged to create value in-terms of accelerated product design cycle and
overall cost reduction by integrating design (geometry), materials, manufacturing and productperformance competencies within a computational environment. The ultimate aim of ICME is to
create a digital thread of entire product development process to design optimal form, material and
manufacturing process. The key consideration for this opportunity is to eliminate the legacy
designs, materials, or manufacturing considerations and relook at the current product engineering
cycle as a white-space opportunity. However, the complexities associated with the prevalent
24
processes, functional silos and disparate IT systems make this transformation very challenging in an
industrial scenario. The current talk would focus on the opportunities of ICME framework for its
near term industrial realization. The possibilities of boot-strapping the available product design and
analysis tools, manufacturing simulation tools, and materials design and processing tools in ICME
framework will be discussed. The status and synergies of ICME with respect to other organizational
initiatives like systems engineering or big-data will be presented. Specific examples on its
applications to emerging technologies such as additive manufacturing will be illustrated.
Furthermore, co-adaption of new materials, manufacturing processes and design philosophies for
more-effectively driving broader initiatives like light-weighting will be discussed with specific
examples. The talk will also provide specific examples of leveraging reduced ordered modeling
methods and available disparate data-sets for specific value creation will be provided. Besides the
technology readiness and business readiness, talent availability in this niche domain is the most
significant challenges for adaption of ICME in industry. The current functional silos of design,
manufacturing and materials engineers with their traditional experience-based expertise would be
the major bottle-neck in the scale-up of this technology in the industry. Finally, the skill-set
required for developing right talent base for this emerging area will be discussed.
Keywords: ICME, big-data, digital thread, additive manufacturing, light-weighting.
Entropy and entropic stabilization of alloy phases
Subramanian Raju
Calorimetry and Materials Modelling Section, Metallurgy and Materials Group,
Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, India.
E-mail: [email protected]
It is well known that at the fundamental level, the stability of an alloy is decided by an intricate
interplay of enthalpy (oHf) and net entropy (oSf) changes that are associated with its formation.
While the former quantity, namely oHf, has been fairly extensively explored on both theoretical
and experimental fronts for a number of binary and limited ternary and higher order systems, its
counterpart, the formation entropy oSf, has seldom received commensurate attention. One obvious
reason is that entropy, unlike the enthalpy increment is not a directly measured thermodynamic
quantity. It is often inferred through accurate heat capacity (Cp) measurements. Nevertheless, a
precise estimation and more importantly the decomposition of oSf into its various microscopic
components is a difficult exercise, to phrase the issue in mild terms. The present study addresses
this issue.
The total formation entropy derives from changes in electronic, magnetic, vibrational and
configurational degrees of freedom that usually accompany the formation of an alloy. Of these,
oSvib, the vibrational entropy contribution may be estimated from conventional Cp measurements.
In the case of crystalline materials, reliable information on phonon density of states, obtained either
via inelastic neutron scattering, or through ab-initio calculations, serves to supplement the primary
calorimetric heat capacity data. In a similar sense, the magnetization measurements can help in
sizing the magnitude of oSmag. While diffraction studies, supplemented again by appropriate
modelling shed light on the structure dependent part of the alloy Hamiltonian, they do not offer a
recipe for estimating oScon, the change in entropy arising from configurational degree of freedom.
This is still a lacuna in the formal thermodynamic theory of alloy phases.
The quantity oScon in its core is a measure of randomness of the alloy. Viewed in this sense, it can
only be estimated through classic statistical prescription of alloy randomness. It is useful to recall
25
that most of the existing prescriptions of oScon, such as point, pair and cluster probability based
descriptions of alloy configuration and hence entropy, do not serve to establish an interpretable link
between oHf and oScon. This is a crucial missing link. Thus for example, while the change in
energy following the disruption of regular periodicity resulting in the formation of a solid solution
can be estimated and measured as well, the entropy conjugate can only be inferred by a Boltzmann
like prescription, if point probability method is adopted. Other sophisticated descriptions are a
natural extension of this axiom.
In this connection, an attempt is made to highlight the fact that even within the framework of
classical thermodynamics, there could be a possible link between oScon and oHf, through Vf, the
volume change accompanying alloying. The theoretical development is traced for a simple
substitutional binary alloy, but the deductions are general in nature. It is conjectured that if oSf
happens to be high, either on configurational ground or otherwise, it must also reflect in Vf, as also
possibly in other thermophysical quantities.
Keywords: Alloys; Thermodynamics; Enthalpy, Entropy, Modelling
Physical metallurgy of high-entropy alloys
Jien-Wei Yeh
Department of Materials Science and Engineering, National Tsing Hua University
E-mail: [email protected]
Physical metallurgy is a branch of materials science, which focuses on the relationship between
composition, processing, crystal structure and microstructure, and physical and mechanical
properties. The progress of physical metallurgy is over 100 years and the underlying principles are
thought to become mature. However, the progress is based on the observations on conventional
alloys. As compositions of HEAs are entirely different from that of conventional alloys, physical
metallurgy principles might need modification for HEAs.
In this presentation, four core effects of HEAs, i.e. high entropy, sluggish diffusion, severe lattice
distortion, and cocktail effects, are reviewed. Their influences on different aspects of physical
metallurgy are emphasized with examples. Most importantly, this presentation points out that lots of
future works are required to build suitable mechanisms and theories correlating composition,
microstructure and properties for HEAs. Only these understandings make it possible to complete the
physical metallurgy of the alloys world.
Keywords: physical metallurgy, high-entropy alloys, four core effects
A combinatorial assessment of AlxCrCuFeNi2 (0<x<1.5)
complex concentrated alloys: microstructure, microhardness,
and magnetic properties
Rajarshi Banerjee1, M. A. Gibson2 and Hamish Fraser3
1
MSE, University of North Texas, Denton, Texas, USA
2
CSIRO and Monash University, Clayton, Victoria, Australia
3
CAMM, The Ohio State University, Columbus, Ohio, USA
E-mail: [email protected]
Since 2004, when the first reports on high entropy alloys (HEAs) first came into the limelight, these
systems have attracted a lot of attention. The paradigm shift, involved the approach of adding
26
elements in equiatomic proportion to create solid-solution face-centered-cubic (FCC) alloys. This
method changed the old approach of adding elements to a „parent‟ element to create alloys. There is
no single dominant matrix element. While single-phase solid solution HEAs are interesting, in
most cases structural materials are incredibly complex systems optimized to provide a demanding
balance of properties often under extreme conditions. Traditionally, this complexity has been
embodied in the alloy microstructure – and the compositions and processing needed to produce
them. High entropy alloys (HEAs) are a new concept to expand the composition space, but the
current focus on single-phase microstructures represents a serious limitation. Therefore the new
emphasis, specifically of interest for high temperature structural alloys, is to expand the scope of
single-phase alloy exploration in HEAs to include the engineered design of multi-phase alloys.
The complexity associated with the vastness of the alloy composition space literally explodes and
combines with the microstructural complexity to form an inter-related set of daunting challenges.
Hence the designation of complex concentrated alloys (CCAs) for this new class of metallic
alloys.
This presentation will discuss a novel combinatorial approach for assessing compositionmicrostructure-microhardness-magnetic property relationships in high entropy alloys, or more
broadly in complex concentrated alloys; using laser deposited compositionally graded
AlxCrCuFeNi2 (0 < x < 1.5) complex concentrated alloys as a candidate system. The composition
gradient has been achieved from CrCuFeNi2 to Al1.5CrCuFeNi2 over a length of ~25 mm, deposited
using the laser engineered net shaping process from a blend of elemental powders. With increasing
Al content, there was a gradual change from an fcc-based microstructure (including the ordered L12
phase) to a bcc-based microstructure (including the ordered B2 phase), accompanied with a
progressive increase in microhardness. Interestingly, with increasing paramagnetic Al content,
saturation magnetization as well as coercivity increases and reaches a maximum value when x=1.3,
indicating the tunability of magnetic properties by a paramagnetic element in this alloy system.
Such graded alloys are highly attractive candidates for investigating the influence of systematic
compositional changes on microstructural evolution and concurrent physical and mechanical
properties in complex concentrated alloys or high entropy alloys.
Challenges in high entropy alloy research
B. S. Murty
Department of Metallurgical and Materials Engineering,
Indian Institute of Technology Madras, Chennai 600036, India
E-mail: [email protected]
HEAs are a new class of multi-component equiatomic (or near equiatomic) alloys, which form
simple solid solutions due to their high configurational entropy. The formation of nanocrystalline
HEAs has made them more interesting due to their fundamental and technological importance.It is
important to note that all multi-component equiatomic alloys do not lead to the formation of single
phase solid solution or for that matter mixture of solid solutions. In a number of cases, these so
called HEAs, have shown the formation of intermetallic phases and in some cases phase separation
of certain elements with high positive enthalpy of mixing with other elements. Prediction of the
phase formation in high entropy alloys is a major challenge in this field. Understanding the stability
the phases is also a major challenge due to the sluggish diffusivity in these alloys. Processing of the
alloys for useful applications is also an important area that is attracting the attention of researchers
in this field. The present paper addresses a number of these issues based on the ongoing work in the
research group of the speaker.
27
Strength of ultrafine-grained high entropy alloys
N. Balasubramanian1 and Terence G. Langdon2
1
9, VLN Prabuddhalaya, 748A Nisarga layout, Bangalore 560083, India.
2
Faculty of Engineering and the Environment, University of Southampton, U.K.
E-mail: [email protected]
Severe Plastic Deformation (SPD) can introduce Ultrafine-Grains (UFG) of submicron and
nanometer (nm) grain size in a material. Equal-Channel Angular Pressing (ECAP) and HighPressure Torsion (HPT) are well known methods of SPD. This paper reviews applications of these
methods to HEA and the associated increase in strength. A CoCrFeNiMn face-centered cubic solid
solution processed by HPT at 6.0 G Pa has an average grain size of 40 nm and shows an expected
increase in hardness as a result of grain refining with a Hall-Petch slope of 27.7 MPa mm½. Another
study on the same alloy shows hardness increasing from 160 HV to 520 HV after HPT at 7.8 GPa
and 5 rotations corresponding to torsional strain of 50. After annealing at 4500C for 100 hours the
hardness increases to 910 HV. These results are explained on the basis of the large number and
nature of grain boundaries introduced by HPT. An as-cast alloy Co21Cr22Cu22Fe21Ni14 contains two
fcc phases, one Cu - rich and the other Cu –lean and a hardness of 190 HV. After HPT the hardness
increases to 470 HV at a strain of 157 with a further increase to 540 HV after a 6500C anneal. The
strengthening is explained by the formation of nano clusters of Cu (2 to 32nm) and the dissolution
and partition of the two Cu phases. A four-fold increase in hardness is observed in an
Al0.3CoCrFeNi after HPT at 6.0 GPa (contributing 82%) and annealing at 5000C. The talk will
illustrate how ultrafine-grain size and unique features of grain boundaries resulting from SPD add
value to high entropy alloys which already have an embarrassment of riches.
Keywords: ECAP, HPT, SPD, HEA and strength.
Advance characterization of materials for high temperature applications
R. Sarkar, M. Z. Alam, C. Mondal, V. Singh, C. Parlikar, S. Saha, D. K. Das and P. Ghosal
Defence Metallurgical Research Laboratory, Kanchanbagh,
Hyderabad-500058, India
E-mail: [email protected]
Microstructures of a material play a very crucial role in controlling its properties. Therefore, proper
characterization of microstructure or different phases in a microstructure is essential for correlating
these with different properties, especially for structure critical materials. In this study, electron
microscopic characterization of three different materials used for different applications will be
presented. (i) In first case, oxidation resistant diffusion Pt-aluminide (PtAl) coatings, which are
applied on advanced gas turbine engine components for enhancing their high temperature
capability, has been studied. The coatings are comprised of the brittle intermetallic B2-NiAl phase
and have a high brittle-to-ductile-transition-temperature (BDTT) of ~600C. Cracks formed in the
coating deteriorate the strain tolerance of the coated components. The present study examines the
role of local microstructure on the tensile failure mechanisms in a PtAl coating using a combination
of SEM-EBSD, Dual beam SEM-TEM and TEM-Precession electron diffraction-OIM systems. The
insights are indispensable for the development and validation of life prediction models for coated
components using the integrated computational materials engineering (ICME) approach. (ii) In
another study, formation of topological closed packed (TCP) phases during service exposure has
been examined, which adversely affect the life of aero-engine components made of Ni-base
superalloys. Deleterious nature of a Cr-rich phase has been identified by analyzing an afterburner
28
fuel manifold. Due to its similarity in electron diffraction patterns and chemical composition of Crrich M23C6 and Cr-Ni rich sigma-phase, respectively, the phase can only be identified after a very
careful examination of high index planes. A combination of dual beam SEM and PED in TEM has
been employed to explore this phase. (iii) Further, EBSD-SEM and TEM-PED-OIM have been used
to identify different phases, such as TiAl (L10), Ti3Al (DO19), TiB, β (B2) and β (B82) in a γ-TiAl
alloy, Ti45Al8Ta2Cr0.2B0.2C (at.%), used for turbine blade application. Studies of these phases are
important to understand the effects of minor elements on microstructure and γ+α2 lamellar structure
on creep behavior of the alloy. Advanced techniques like, FIB, TEM-PED-OIM and EBSD are used
to characterize the precise phases in these three materials and will be discussed in the paper.
Keywords: Characterization, phases, precession electron diffraction, high temperature material
Effect of quasicrystalline phase on the microstructure and
mechanical properties of magnesium alloys
Alok Singh
Structural Materials Unit, National Institute for Materials Science, Tsukuba, Japan
E-mail: [email protected]
To reduce greenhouse gas emissions from ever rising number of automobiles, it is important to
reduce the weight of automobiles. This can be achieved by use of magnesium alloys, which are the
lightest structural alloys. However, these alloys suffer from low strength and ductility due to strong
basal texture.
It is well known that quasicrystalline (QC) phases form as stable phases in Mg-Zn-RE (RE=rare
earth) alloys. The QC phase can modify the microstructure and texture of the alloys by affecting
dynamic recrystallization during wrought processing. QC particles refine the microstructure by
stimulating dynamic recrystallization, and stabilize the microstructure by pinning grain boundaries
and resisting coarsening. The texture of the alloy is modified by nucleation of α-Mg in various
crystallographic orientations over QC particles during recrystallization. The QC phase particles
make epitaxial low energy interfaces with the crystalline matrix.
Various microstructures of QC phase in Mg-Zn-RE alloys will be shown by advanced transmission
electron microscopy, which result in extraordinary combination of strength (yield strength of 400
MPa) and ductility (12-15%).
Keywords: Magnesium alloys, quasicrystal, microstructure, transmission electron microscopy,
mechanical properties.
Refined microstructures in metastable beta titanium alloys – role of nonconventional transformation pathways
Yufeng Zheng1, Rajarshi Banerjee2 and Hamish Fraser1
1
CAMM, The Ohio State University, Columbus, OH, USA
2
MSE, University of North Texas, Denton, TX, USA
E-mail: [email protected]
The subject of microstructural evolution in metastable β titanium alloys has attracted much attention
recently. Thus, compared with conventional microstructures in -β Ti alloys, typically involving
29
fairly coarse lamellae of the  phase in either the colony or basket weave arrangement depending
on heat treatment conditions, various size scales of refined intragranular  microstructures can be
produced in metastable β Ti alloys. In this current research, three different size scales of 
microstructure, termed refined, more-refined and super-refined microstructures, have been
characterized in the same metastable β Ti alloy, Ti-5553. These various distributions have been
produced by exploiting the influences of compositional and/or structural instabilities on the β → 
transformation, using various non-conventional transformation pathways. The refined
microstructure is formed by the mechanism of pseudo-spinodal decomposition, involving
thermally-activated compositional fluctuations about the appropriate Co(T) composition within the β
matrix. Metastable phases, such as the β phase and bcc structure β‟ phase, can also alter the local
concentration and/or structure and therefore potentially affect subsequent  precipitation. The
more-refined and super-refined microstructures are formed exploiting this metastability,
specifically the indirect and direct influences of the pre-formed, uniformly distributed metastable β
phase in a  phase matrix. The formation mechanisms of these various forms of ultrafine 
microstructures will be compared and contrasted in terms of these nano-scales compositional and/or
structural instabilities in the  phase matrix in metastable β titanium alloys.
The support of the US NSF under grant DMR-1309270 and DMREF grant DMR-1435483 is
gratefully acknowledged.
Keywords: titanium alloys, refined microstructures, phase transformations, aberration-corrected
electron microscopy
Phase transition and anomalous diffusion in metastable β Ti-Mo*
Niraj Gupta, S. Banerjee and Srinivasan G. Srivilliputhur
University of North Texas, Denton, TX, USA
E-mail: [email protected]
Formation of the hexagonal omega phase at the nanoscale by quenching beta titanium alloys, with a
low concentration of beta stabilizing additions, and its subsequent transformation to the
thermodynamically stable a phase upon annealing have been extensively studied experimentally for
over 50 years. However, several significant questions on the atomistic mechanisms driving such
transformations persist to date. Using ab-initio methods, we have studied a prototypical Ti-Mo
system to understand the effect of Mo distribution on the phase transformation mechanisms. We
address the following important questions: (i) How does an optimum level of molybdenum stabilize
the ω phase? Can ω transform to the α-phase in the crystal bulk or only at high-energy regions such
as grain boundaries. Furthermore, can atomic configurations within ω particles act as embryos for
nucleation of the α phase? (ii) Experiments reveal that many ω forming alloys exhibit anomalous
(non-Arrhenius) diffusion behavior. What is the atomistic mechanism responsible for such
anomalous diffusion? Importantly, how does temperature and concentration of beta stabilizing
elements influence anomalous diffusion?
*Funded by the National Science Foundation
30
Surface mechanical and structural characterization to understand domains of
tribology in automotive engines
Anirban Mahato1, Nisha Verma2, V. Jayaram2 and (late) S. K. Biswas1
1
Department of Mechanical Engineering
2
Department of Materials Engineering
Indian Institute of Science, Bangalore 560012
E-mail: [email protected]
When steel piston rings rub against aluminium-silicon cylinders, there are multiple domains of
wear, depending on speed and load. The ones which lead to significant material removal are
important in that they dictate what happens when lubricant is lost or at times of piston reversal. In
contrast, the domain of what is called ultra-mild wear (UMW), which is the one in which engines
operate for the bulk of their lifetime, corresponds to a situation where the wear rates are vanishingly
small over extended periods of time. Termination of this period leads to transitions to higher wear
rates and loss of engine performance. In all these domains, the surface thickness over which
microstructural changes take place ranges from a few nanometers (UMW) to a few micrometres
(severe wear).
During UMW, protruding silicon needles on an etched/honed Al-Si alloy surface accommodate the
contact load. Over time, these needles undergo a variety of changes, including tilting, sinking into
the Al matrix or fracture, that can be tracked by AFM. The transition to a finite wear regime of
progressively greater severity coincides with true metal-metal contact and plastic deformation of the
Al-alloy matrix. At the other extreme, during severe wear, the surface displays dramatic changes
over the top few micrometres. Oxide layers alternate with severely re-organised microstructures
created by the fragmentation and channeling of silicon, accompanied by severe plastic deformation
of the metal matrix which lead to sub-grains of 50-300 nm, recrystallisation of sub-100 nm grains
and eventually the nucleation of voids in the Al-solid solution. The degradation in matrix properties
is seen through a reduction in the elastic modulus of the top 1-2 micrometres as measured through
nanoindentation and from TEM observations of the wear track. Cracks nucleating in silicon
particles link through the softened matrix.
This presentation will demonstrate the critical role that high resolution characterization techniques
(FIB, AFM, TEM) can play in elucidating the mechanisms of material removal and help in
formulating models of wear in different ranges of pressure.
Keywords: Wear, Al-Si, tribology, microstructure
Microstructural evolution and structure-property relationships of mushy state
rolled in-situ Al-4.5Cu-5TiB2 composite
Monalisa Mandal and Rahul Mitra
Department of Metallurgical and Materials Engineering,
IIT Kharagpur – 721302, West Bengal
E-mail: [email protected]
Mushy state forming of discontinuously reinforced Al-alloy matrix composites is of interest due to
lower flow stress required for deformation, redistribution of particles and refinement of dendritic
microstructure found originally in as-cast condition. In this study, Al-4.5Cu-5TiB2 composite plates
were processed by stir-casting route with TiB2 particles having 1.5 μm size being precipitated in31
situ by reaction between K2TiF6 and KBF4 salts. The as-cast composite samples were subsequently
subjected to 5% reduction in thickness either by hot rolling at 370 oC, or mushy state rolling at
626oC or 632oC, so as to have liquid content of 20 or 30 vol.% liquid, respectively during rolling.
Thereafter, the microstructures were examined using optical, scanning, and transmission electron
microscopy, whereas grain orientation imaging was carried out by electron backscattered diffraction
(EBSD). It has been observed that mushy state rolling of the composite leads to formation of
globular-shaped grains with bimodal size distribution. During passage through the roll-gap, the
liquid is squeezed to the surface, which is followed by its rapid solidification in contact with the
rolls to form equiaxed finer matrix grains. Observation of such grains around TiB2 or CuAl2
particles using EBSD analysis confirms their role as active sites for nucleation. Furthermore, the
matrix grains away from the surface have shown the formation of low angle boundaries, which is
suggestive of dynamic recovery within unmelted grains during rolling. In contrast, more or less
uniform grain structure caused by particle stimulated dynamic recrystallization is observed in the
hot-rolled composites. The mushy-state rolled composites are found to exhibit enhanced aging
kinetics, hardening of rolling surface as well as improvement in strength, ductility, creep and wear
resistance as compared to as-cast or hot-rolled samples. The relation of mechanical properties with
the microstructure and grain orientations evolved through mushy-state rolling will be discussed.
Keywords: composite, mushy state rolling, microstructural evolution, dynamic recrystallization,
mechanical properties.
Nanoscale quantitative magnetic information and probing optical band gap by
HR-EELS in an aberration corrected transmission electron microscope
Ranjan Datta
International Center for Materials Science,
Jawaharlal Nehru Center for Advanced Scientific Research,
Bangalore 560064
E-mail: [email protected]
In this presentation I will demonstrate how to obtain quantitative magnetic information at nanoscale
by two different techniques i.e. EMCD and HR-EELS from a specific area of interest with
comparative advantages between the two approaches. I will highlight several of our contributions in
terms of developing the understanding and associated experimental techniques. I will then explain
on how HR-EELS is an extremely powerful nanoscale optical band gap probing technique with a
particular focus on important nano-dimensional materials of MoS2 and ReS2. I will end my
presentation with a brief account on future direction towards obtaining materials information
beyond structure based on purely imaging approach.
Phase separation in Ce-Al (Ga) metallic glass
R. S. Tiwari
Department of Physics, Nano–Science and Technology Unit,
Banaras Hindu University, Varanasi-221005, India
E-mail: [email protected]
In recent years, rare earth-based metallic glasses have attracted considerable attention due to their
novel physical properties. They refer to glass forming ability, mechanical, magnetic, super-plastic
and thermoplastic properties in super-cooled liquid region and hold promise for many future
32
applications. A large number of novel rare earth based metallic glasses, such as La-, Ce-, Er-, Y-,
Sm- based metallic glasses have been synthesized recently. Out of these, Ce-based metallic glasses
are special because of their unusual behavior linked to 4f electrons. One of the intrinsic features of
Ce is its variable electronic structure and valance states. Thus, only small amount of energy is
required to change the relative occupancy of the electronic levels e.g. when Ce is subjected to high
pressure or low temperatures, a volume change of approximately 10% results. Therefore, the
structural and physical properties of Ce-based metallic glasses may have characteristics which are
different from other known metallic glasses. The first report of phase separation in metallic glass
(MG) by Chen and Turnbull in Pd-Au-Si alloy, has attracted considerable attention due to their
unique microstructural variations of amorphous phases at different length scales. Following this,
many authors have investigated the possibility of phase separation in MG compositions. Such a
phase separation is however, incompatible with one of the glass forming criteria of negative heat of
mixing. In our latest investigation, we have reported phase separation of Ce75Al25 alloy after Ga
substitution. The XRD, SEM and TEM investigations carried out on Ce75Al25-xGax (x=2, 4 and 6)
have clearly demonstrated the coexistance of two amorphous phases.In the proposed talk the results
of our recent work on phase separation will be presented.
Keywords: Metallic glass, Phase separation, X-ray absorption spectroscopy.
Self-accommodation in nanocrystalline NiTi shape memory alloys
Gouthama
Department of Materials Science and Engineering,
Indian Institute of Technology, Kanpur, 208016, UP, India
E-mail: [email protected]
Shape memory alloys (SMAs) are used in a variety of engineering and biomedical applications.
Among various SMAs, near equi-atomic Ni-Ti alloys have emerged as one of the most
preferredalloy system because of their superior shape memory effect (SME) and superelastic effect
(SE), mechanical properties, corrosion resistance and biocompatibility. The basis for these
properties arises from the reversible crystallographic transformation from the high temperature
cubic B2 structure (austenite phase) to the low temperature monoclinic B19 (martensite phase)
structure. The martensite phase usually consists of many twin variants accommodated in low energy
configurations. In Ni-Ti alloys, as many as 24 self-accommodating twin variants are possible. The
interfaces between martensite variants are highly glissile. The reversible crystallographic
transformation occurs on thermal cycling between the martensite and austenite phase so that the
material recovers its original shape. Self-accommodation among variants by the collective
displacement of atoms from one crystal structure to another structure occuring without a
macroscopic changes in the shape of the material.
Several crystallographic theories have been developed relating the atomic arrangements of the
atoms in the parent and twinned crystals. A brief review of these classical theories will be provided
highlighting the essence of self-accommodation. One of the most recent among these theories
considers clustering of two V-shaped morphologies resulting in a rhombic-shaped selfaccommodation morphology fully compensating the shape strain due to the transformation.
Generally, these theories presume coarse grained structures. There are some attempts to understand
self-accommodation in nanocrystalline NiTi SMAs. This presentation brings together some of
these recent experimental results and theoritical ideas on self-accommodation in fine grained
materials.
Keywords: Self-accommodation, NiTi SMA, Nanocrystalline SMA, Interfaces, Electron
Microscopy
33
Stabilization of coherent precipitates in nanoscale thin films
Pooja Rani1, Arun kumar2, B.Vishwanadh3, Somnath Bhattacharyya4,
R. Tewari 3 and Anandh Subramaniam1
1
Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur-208016
2
Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur-208016
3
Materials Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085
4
Metallurgical and Materials Engineering,
Indian Institute of Technology Madras, Chennai 600036
E-mail: [email protected]
*
Coherent precipitate beyond a critical size precipitates, on growth beyond a critical size ( rbulk
),
become semicoherent by the presence of interfacial misfit edge dislocations. In the case of
precipitation in 'small' domains (matrix), the strain energy of the precipitate is altered with respect
to its value in bulk domains; due to a lesser volume of strained material and domain deformations,
resulting from the proximity of free surfaces. This results in a change in the value of critical size for
the coherent to semi-coherent transition of the interface. In the current work, the Cu-2wt.% Fe
system is used as model system to study the coherent to semi-coherent transition of precipitates. In
this system spherical Fe-2wt.% Cu precipitates form, which become cuboidal on growth beyond the
critical size. Transmission electron microscopy is used to show experimentally for the first time
*
that, a coherent precipitate can be stable beyond rbulk
, in nanoscale free-standing thin films (i.e.
*
*
critical size for coherent to semi-coherent transition for thin films ( r film > rbulk
). Electron Energy
Loss Spectroscopy has been used to determine the thickness of the sample. In parallel, finite
element simulations are used to compute the critical size in representative domains and to
comprehend the energetic basis for the observed phenomenon. Eigenstrains are used to simulate the
precipitation process and the stress state due to an interfacial misfit dislocation in the finite element
model. Important findings include: (i) strain energy versus precipitate-size plot shows change in
curvature for large precipitate sizes and (ii) coherent state is stable in two distinct regimes of
precipitate sizes. Further, a phase diagram showing the stability regions of the coherent and semicoherent states of the precipitate is drawn.
Keywords: Precipitation, Nanoscale Thin Films, Transmission Electron Microscopy, Finite
Element Method.
Understanding solidification of alloys through study of
glass/crystal composites
G. K. Dey
Materials Science Division, Bhabha Atomic Research Centre, Mumbai, India-400085
E-mail: [email protected]
Unlike in a crystal where the description of the arrangement of motif is enough to generate the
whole structure, the description of the structure of a glass involves several components like
knowledge of the short range order (SRO), medium range order (MRO), the exact correlation
between the adjacent medium range ordered domains and finally a description of the open space in
the structure because all glasses are more open compared to their crystalline counterparts. In this
study, the amorphous structure has been probed from the smallest length scale corresponding to the
short range order and pair distribution function to medium range order and finally to the overall
structure invoking the existence of pores. Whereas the short range order depicting the polyhedra
34
formed by the first nearest neighbours has been construed from EXAFS correlated with modeling,
the symmetry of the clusters has been established by angstrom beam electron diffraction. The
medium range order has been established by small angle x-ray diffraction and fluctuation
microscopy in the image and diffraction modes. These techniques have given a measure of the
length scales of the medium range ordered clusters with the values from one technique
corroborating that from the other. The joining of the clusters for building the structure from SRO to
smaller length MRO has been investigated and a very good estimate has been obtained by angstrom
beam electron diffraction. The structure beyond the MRO length scale has been assembled by
estimating the pores by three techniques: differential scanning calorimetry, positron annihilation,
and filtered high resolution electron microscopy. The experimental results on SRO, MRO and pores
has been admixed to generate the structure of glass by using a model.
It is important to understand the structure of glass very well for understanding solidification because
the structure of the liquid and that of the glass have a very strong similarity. Besides fully
amorphous alloys, the structure of composites obtained by cooling the liquid at rates slightly lower
than those required for full glass formation were also analyzed. These comprised crystals embedded
in a glassy matrix. A variety of crystals/glass interfaces could be encountered. The origin of these
crystal morphologies and interfaces were examined very critically by different characterization
tools with local solidification conditions (cooling rate) in view. These results have been analyzed
and their importance in understanding solidification has been brought out.
Toughness of metallic glasses
Shantanu V. Madge
CSIR-National Metallurgical Laboratory, Jamshedpur
E-mail: [email protected]
Bulk metallic glasses (BMGs) have certain attractive properties, but their toughness can show much
variation, depending on the kind of test and alloy chemistry. This talk discusses the factors that influence
fracture toughness. It is shown that even the less-tough metallic glasses are tougher than oxide glasses. The
widely-accepted theories describing the links between toughness and material parameters, including elastic
constants and alloy chemistry (ordering in the glass), are critically evaluated. Examples will be provided of
how careful microstructural design of BMG-based composites can help in achieving remarkable strengthplasticity combinations, even in less-tough glasses such as those based on La. The ideas on strength and
toughness are directly applicable to the use of metallic glasses in hard coatings, and recent work by the
author in this area will be highlighted. Finally, a few important topics for further work are identified.
Miller-Bravais indexing scheme: Beyond its classical form
Rajiv Kumar Mandal
Department of Metallurgical Engineering, IIT (BHU), Varanasi-221005, India
E-mail: [email protected]
The Miller-Bravais indexing scheme has been shown to be useful for hexagonal crystals. The three
dimensional periodic crystals possess rank of three. The designation of planes and directions in
terms of four indices is made unique by imposing condition on the sum of three indices that are
coefficients of three basis vectors in the hexagonal plane. It takes such a sum to be zero in its
classical form. The purpose of this presentation will be to propose a general form of such a
condition. A critical appraisal of such a choice in terms of four- dimensional formalism will be
35
given. It will be shown that Miller-Bravais indexing scheme is a sub-case of such a general
formalism.
Keywords: Miller-Bravais, hexagonal crystal, indexing, four-dimensional formalism
On teaching of crystal dislocations: Misconceptions and models
R. Prasad
Department of Applied Mechanics
Indian Institute of Technology Delhi, New Delhi, India, 110106
E-mail: [email protected]
I would discuss two common misconceptions that occur in teaching of dislocations at the
undergraduate level. First misconception relates to the half-plane associated with a dislocation.
Most textbooks give the impression that an edge dislocation comes with a unique extra half-plane
associated with it, this plane being perpendicular to the slip plane. But this is not true. An edge
dislocation has a unique slip plane associated with it. One side of this plane is the „extra‟ side and
the other, the „missing‟ side. Any plane ending on the dislocation line from the extra side is a
possible extra half-plane. The second misconception is related to the helicoidal planes associated
with screw dislocation. However, edge dislocations also have helicoidal planes associated with it. In
fact, in a classic book by Cottrell, this has been taken as a defining property of a dislocation line. In
the end, I will also discuss how to build models of dislocations, in particular a model of a straight
mixed dislocation.
Optical dilatometer: A new way to understand and quantify sintering kinetics of
iron ore pellets
T. K. Sandeep Kumar1, N. N. Viswanathan3, H. Ahmed1, 4 and C. Andersson2
1
Lulea University of Technology (LTU), Lulea, Sweden
2
Luossavaara-Kiirunavara Aktiebolag (LKAB), Gällivare, Sweden
3
Indian Institute of Technology Bombay (IITB), Mumbai, India
4
Central Metallurgical Research & Development Institute (CMRDI), Cairo, Egypt
E-mail: [email protected]
Pelletizing and briquetting are the agglomeration techniques practiced widely across the world. Fine
particles adhered, and strengthened when exposed to high temperatures. Sintering is an important
phenomenon for powder compacts and pellets during their in duration process. Sintering is
becoming more important for a wide range of materials from the field of ceramics, composites,
pharmaceutical, refractory, nuclear, minerals and ores. Sintering mechanism was determined by
capturing their shrinkage and estimating their kinetic parameters. A recently innovated optical
dilatometer captures the shrinkage two dimensionally, instead of traditionally used linear push-rod
dilatometer. Experiments with iron ore pellets (magnetite and hematite)of 10 mm diameter have
been performed to compare both the dilatometers. Optical dilatometer works on the principle of
optics capturing shadow images, hence eliminating the physical interference with pellets. Therefore,
the kinetic parameters estimated for different materials are more representative of the actual
process. This gives a relatively simpler and more precise methodology to estimate the optimum
process parameters for various raw materials which can be beneficial considering their variability
and mix.
36
Orientation sensitive deformation in Zr alloys: experimental and
modeling studies
D. Srivastava1, S. K. Jha2, N. Keskar1, K.V. Manikrishna1, G. K. Dey1 and N. Saibaba2
1
Materials Science Division, Bhabha Atomic Research Center
2
Nuclear Fuel Complex, Hyderabad
E-mail: [email protected]
Zirconium alloys are used for fuel cladding and other structural components in pressurised heavy
water nuclear reactors (PHWR‟s). Currently there is a lot of interest in developing alloys for
structural components for higher temperature reactor operation. There is also need for development
of cladding material with better corrosion and mechanical property of cladding material for higher
and extended burn up applications. The performance of the cladding material is primarily
influenced by the microstructural features of the material such as constituent phases their
morphology, precipitates characteristics, nature of defects etc. Therefore, the microstructure is
tailored as per the performance requirement by through controlled additions of alloying elements,
thermo-mechanical- treatments. In order to obtain the desired microstructure, it is important to
know thedeformation behaviour of the material.
Orientation dependent deformation behavior was studied in Zr using a combination of experimental
and modeling (both discrete and atomistic dislocation dynamics) methods. Under the conditions of
plane strain deformation, it was observed that single phase Zr, had significant extent of deformation
heterogeneity based on local orientations. Discrete dislocation dynamics simulations incorporating
multi slip systems had captured the orientation sensitive deformation. MD dislocations on the other
hand brought the fundamental difference in various crystallographic orientations in determining the
nucleating stress for the dislocations. The deformed structure has been characterized using X-ray,
electron and neutron diffraction techniques. The various operating deformation mechanism will be
discussed in this presentation.
Iron age high-tin bronzes from Tamil Nadu and comparisons with
South-east Asia
Sharada Srinivasan
National Institute of Advanced Studies, Bangalore
E-mail: [email protected], [email protected]
The southern Indian and Tamil region supported some rich and distinctive continuing artistic
traditions in antiquity for which it is justifiably well known. These include the spectacular cast
images of the Chola period. Analytical investigations by the researchers using techniques such as
ICP-MS showed that several representative images from collections including the Victoria and
Albert Museum and Government Museum Chennai showed that they were of leaded bronze.
However, it seems that the use of skilled alloys of higher tin bronze were made exploiting their
special properties for making artefacts with specific purposes going back to early antiquity.
Generally speaking, as-cast binary copper-tin alloys with over 15% do not seem to have been
widely used in antiquity. Nevertheless, the use of the unusual and skilled binary bronze alloys of a
higher tin content are reported from various contexts in Indian antiquity and skillfully manipulating
the high temperature intermetallic compounds properties of bronzes. In particular the specialized
use of the hot forged and quenched high tin beta (23%) bronze was used to skillfully make vessels
with finds reported by the author through archaeometallurgical studies from numerous peninsular
and south Indian megalithic/Iron Age contexts of the early to late first millennium BCE ranking
37
amongst the early such finds known such as from the Nilgiris and Adichanallur in Tamil Nadu and
with continuing traditions particularly in Kerala. Another exotic high tin-bronze craft tradition that
thrived in Kerala is the making of mirrors of delta bronze exploiting the silvery delta compound of
bronze of around 33% to get a good reflective surface as shown in past studies by the author. The
broader Asian and southeast Asian context is also touched upon for comparative insights and in
relation to broader Indian influences.
Keywords: High tin beta bronze Iron Age Archaeometallurgy quenched vessels
Advanced materials technologies for structural component repair
Dheepa Srinivasan
GE Power
GE India Technology Center, EPIP-II, Whitefield, Bangalore 560066, India
E-mail: [email protected]
A glimpse of the current industry efforts towards materials technologies used in refurbishment of
structural gas turbine components, including welding, coatings and additive manufacturing will be
shared. One of them makes use of the cold spray coating process as an alternate to conventional
welding, for refurbishment of components. The technology development from a coupon level to a
component level, using the new spray on welding process of repair, will be shared. The second case
study will highlight the efforts in repair using additive manufacturing technique of direct metal laser
sintering (DMLS) to restore a severely damaged part on a Cobalt based superalloy, after service
exposure. Gas turbine blades have oxidation protection coating, on the internal and external surface.
These are typically made of thermally sprayed MCrAlY and diffusion Aluminide coatings. A map
of the coating degradation after service exposure serves as a good indicator of the part temperature.
The key microstructural aspect in the MCrAlY coating is the beta-NiAl phase that is responsible for
the superior oxidation resistance of the coating. In the third study, a Larson Miller parameter type of
approach was used to estimate the coating residual life, and thereby in enabling coating and
component life extension.
Solidification microstructure and temperature field
during normalcasting of Al-3Fe alloy
Fuxiao Yu, Yafei Jia, Fang Liu, Dazhi Zhao
School of Materials science and engineering, Northeastern University,
Shenyang 110819, People’s Republic of China
E-mail: [email protected]
Ultra-fine Al-Al6Fe eutectic microstructure can be generated in Al-Fe alloys with chemical
compositions close to or beyond the equilibrium Al-Al3Fe eutectic point through proper casting. In
this study, in situ measurements of temperature field during iron mould casting of Al-3Fe alloy with
a mould temperature of 15℃, 50℃ and 80℃ at a pouring temperature of 810℃ were investigated.
The results show that mould temperature affects the metastable Al-Al6Fe eutectic temperatures
through bulk undercooling. The corresponding microstructuresin different cooling conditions were
investigated to analyze the correlation between the solidification microstructure and the thermal
field.
Keywords: hypereutectic; Al-Fe alloy; normal casting; thermal measurement; microstructure
38
Oxygen dissolved in wrought iron
Kazuhiro Nagata
Professor Emeritus of Tokyo Institute of Technology, Japan
E-mail: [email protected]
Pre-modern ironmaking and steel making were performed to produce wrought iron. Wrought iron
was decarburized under the molten steel existed with solid one covered by molten FeO at high
temperature. Then, molten steel reacted with molten FeO to produce gas bubbles of CO, while
oxygen dissolved into molten steel. Temperature cyclically increased and decreased around the
melting point of steel and oxygen finally fixed as a solute in the state of oversaturation in solid
steel. About 0.2 mass% of oversaturated oxygen dissolved in old nails used in wooden shrines and
temples in Japan. The mechanisms of dissolution of oversaturated oxygen into steel is
thermodynamically discussed.
The indigenous Hafnium metal: A journey from crust to space
S. C. Sharma and A. K. Shukla
Materials & Metallurgy Group
Vikram Sarabhai Space Centre (VSSC)
Trivandrum 695022
E-mail: [email protected]
Hafnium, a refractory metal, is an essential part of columbium based high temperature alloys which
find performance-critical thermostructural applications in rocket-engines. It is also critically needed
for important applications in the other advanced technology sectors such as nuclear and defense.
Hf‟s large neutron capture cross-section makes it a good material for neutron absorption in control
rods in nuclear power plants. Some semiconductor fabrication processes employ Hf and herein the
oxide of Hf is a preferred choice for integrated circuits at 45 nm and smaller feature lengths.
Filaments and electrodes are also made of Hf metal.
This refractory metal does not exist as a free element in nature, but is found combined in solid
solution with zirconium in natural zirconium compounds such as zircon, ZrSiO4. However, the
chemistry of hafnium and zirconium is so similar that the two cannot be separated on the basis of
differing chemical reactions. Solubility in solvents is the major difference in the chemistry of these
twin elements. Therefore, liquid-liquid extraction processes with a variety of solvents are mostly
used for production of Hf.
Considering the strategic nature of Hf metal for Indian space programme, VSSC in technical
collaboration with C-MET, Hyderabad has recently established the Hf Sponge Production Plant at
C-MET. After developing the Hf extraction technology at lab scale, scaling-up was done first at
pilot scale and subsequently production plant was designed, set-up and successfully commissioned.
The Plant has, initially, an annual production capacity of 320 kg which will meet the requirement of
our space programme.
The plant is based on the solvent extraction method and Hf sponge is derived
(Zr) Raffinate after a series of complex processing steps which include Zr
extraction, calcination, carbo-chlorination, Kroll reduction, and magnesium
indigenous Hf sponge has been further processed successfully through Electron
39
from Zirconium
removal, solvent
separation. The
Beam Melting to
realize Hf metal ingots with specified chemical composition for producing columbium based alloys
for space applications.
Microbially assisted processes in mineral processing, extractive metallurgy and
environmental remediation
S. Subramanian
Department of Materials Engineering,
Indian Institute of Science, Bengaluru- 560012
E-mail: [email protected]
Microbial life has been closely intertwined with the geosphere for nearly the entire history of the
Earth. Microorganisms have a tremendous influence on their environment through the transfer of
energy, charge, and materials across a complex biotic mineral-solution interface. Natural
phenomena driven by the microbe-mineral interactions are incredibly diverse, including major
environment and geochemical processes. Much of the impetus to study the mineral-bacteria
interaction arises from the expected impact on many technological areas, including protection
against bacterial infection and biofouling, bioremediation of organic, inorganic and radioactive
contaminants, microbial fuel cells, bio-leaching, and bio-flotation. With the gradual depletion of
high-grade ores and the finer dissemination of values in the currently processed ore bodies, it has
become imperative to develop appropriate technologies to process such lean grade, refractory ores.
Recent developments in biotechnology not only offer an attractive alternative to aid the processing
of such ores, but also facilitate the remediation of environmental problems resulting from mining
wastes. In this talk, some examples of the studies carried out on the use of microorganisms and their
direct derivatives in mineral processing, hydrometallurgy and in bioremediation of mineral industry
discharges will be highlighted.
Thermo-mechanical simulation of austenite recrystallisation and softening
during hot rolling of line pipe steel
Manjini Sambandam, Pranav Tripathi and Satishkumar Dabbiru
JSW Steel Limited, Vijayanagar Works, Karnataka, India - 583275
E-mail: [email protected]
High strength line pipe grade steel requires low YS/TS ratio, low DBTT and nearly 100% ductile
shear area in drop weight tear tests. These requirements are met by combination of micro-alloying
and microstructure control. Microstructure with polygonal ferrite and carbides offer excellent
DBTT and shear area properties but often high in YS/TS ratio. Acicular ferrite provides
combination of low YS/TS ratio and low DBTT. The shear area largely depends on the prior
austenite grain size. Finish rolling is carried out below Tnr temperature to obtain refining of
austenite grains through strain accumulation. However, during the interpass time of rolling,
softening of austenite through recovery and/or recrystallisation occurs which results in larger
austenite grain size at the end of hot rolling. The extent of strain accumulation or softening is
influenced by the temperature, strain and strain rate of deformation and the inter-pass time. The
softening behavior of selected line pipe grade steel during hot rolling is studied using Gleeble
thermo-mechanical simulator. Two hit method has been employed to study the softening behavior
of the steel during the deformation. Fraction of softening has been calculated for various inter-pass
intervals for pre-determined temperature and strain rate. Range of temperature, strain rate and
strain are selected to represent hot rolling both in plate mill and tandem strip mill. A three
40
dimensional empirical model has been developed to determine the accumulated strain energy and
softening at the end of the hot rolling process. Hot strip rolling has been simulated through
continuous multi deformation tests. The results of two hit isothermal deformation are correlated
with the multiple deformation and the fraction of softening calculated from the model is compared
with the results of multiple deformation simulation.
Keywords: thermo-mechanical simulation, line pipe steel, hot rolling, austenite recrystallisation,
flow softening
Effect of heat treatment on microstructure and hardness of high-strength low
alloy (HSLA) steel bulb bars
Paramanand Bairwa, Nirmalya Rarhi and R. Balamuralikrishnan
Defence Metallurgical Research Laboratory, Kanchanbagh P.O., Hyderabad, India
E-mail: [email protected]
Advanced steels for naval hull applications have to meet a combination of room temperature
strength (both yield and tensile) and sub-zero temperature impact toughness properties. High
strength low alloy (HSLA) steels are good candidate materials, and are often chosen for these
applications, with the hull being made mainly of large plates and stiffeners called bulb bars (see
Figure). Bulb bars have an asymmetric cross-section and are required in many section types (linked
to the dimensions of the cross-section) and in lengths of up to 12m. They are manufactured from
billets of suitable rectangular or square cross-section through a multi-stage section-rolling process
to achieve the profile and subsequently heat treated, by water quenching and tempering, to achieve
desired properties.
Experimental laboratory scale studies, guided by thermodynamic computations using
ThermoCalcTM, were undertaken to arrive at the optimum austenitizing and tempering temperatures
for heat treatment of bulb bars at industrial scale. The studies focused on austenitizing at either 900
or 930oC followed by water quenching and subsequent tempering in the range of 600-650oC. In the
final heat treated condition, large variations in hardness (in excess of 150VHN) were observed for
some treatments, while certain other treatments yielded a variation of only 20-30VHN. Detailed
microstructural evaluation, using light and scanning electron microscopy, were carried out in an
attempt to understand the observed variations in hardness as a function of location and heat
treatment. The results of this study will be presented and discussed, along with potential
implications for heat treatment at industrial scale.
Keywords: HSLA steels, bulb bars, water quenching and tempering, hardness, microstructure.
41
The quest for superhydrophobic metals
M. S. M. Saifullah1, Li Xue1, Jarrett Dumond2, Yee Chong Loke1, Suhui Lim1,3, Hong Yee Low2,
and Karen S. L. Chong1
1
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and
Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore 138634, Republic of Singapore
2
Engineering Product Development, Singapore University of Technology & Design, 8 Somapah
Road, Building 1, Level 3, Singapore 487372, Republic of Singapore
3
Department of Electrical and Computer Engineering, National University of Singapore, 21 Lower
Kent Ridge Road, Singapore 117576, Republic of Singapore
E-mail: [email protected]
Metallic superhydrophobic surfaces may find potential applications in industries prone to corrosion
such as transport and heavy machinery, especially outdoor and portside equipment. The surfaces of
metals are generally hydrophilic due to the presence of polar nature of thin oxides that form with
the reaction with atmosphere. Hence in the case of metals, physical and chemical methods are
employed to realize hydrophobic surfaces. Physical methods such as plasma etching, laser treatment
and growth of metal nanostructures lead to surface roughening whilst self-assembled surface
monolayers and long chain non-polar polymer coatings gives rise chemical modification of the
surface. Both these methods suffer from the disadvantage that it requires an extra cycle of surface
treatment in order to achieve hydrophobicity. Here, we describe a physical process involving
nanoimprint lithography which can potentially be incorporated during the metal working process in
the form of warm / hot working to impart hydrophobic and potentially superhydrophobic behaviour,
without altering the chemical purity of the metal. Here a sheet of metal is pressed against a mold
with patterns on the surface at hot working temperature. This leads to flow of metal into the
crevices of the mold, leading to the formation of sub-micron or nanoscopic surface relief features
responsible for hydrophobic behaviour in metals.
Keywords: Nanoimprint lithography; metal working; mechanical metallurgy; superhydrophobicity
Biomedical imaging using nanoparticles
N. Venkatesha and Chandan Srivastava
Department of Materials Engineering,
Indian Institute of Science, Bangalore, India
E-mail: [email protected]
Magnetic resonance imaging (MRI) is widely used as a diagnosis tool in medical science. Image
contrast enhancing agents are employed to enhance the sensitivity of the MRI technique. This talk
will illustrate the potential of the following materials as contrast agents for MRI: (a) graphene oxide
(GO)-Fe3O4 nanoparticle composite (b)MnFe2O4-Fe3O4 core-shell nanoparticles and (c) CoFe2O4ZnO core-shell nanoparticles. In the case of the work on graphene oxide-Fe3O4 nanoparticle
composites, it will be illustrated that the GO-Fe3O4 composite framework that contains graphene
oxide with least extent of reduction of the carboxyl groups and largest spacing between the
graphene oxide sheets provides the optimum structure for yielding a very high transverse proton
relaxivity value. In case of work on MnFe2O4-Fe3O4 core-shell nanoparticles, it will be illustrated
that the proton relaxivity value obtained in the dispersion of the core-shell nanoparticles is
considerably greater than the proton relaxivity value obtained in the presence of single phase
nanoparticles of the core and shell phases. In the work on CoFe2O4-ZnO core-shell nanoparticles
the effect of two different core-shell geometries on proton relaxivity value will be discussed. It will
be shown that a fluorescent CoFe2O4-ZnO core-shell nanoparticles with the unique geometry in
which CoFe2O4 ferrite nanoparticles agglomerates are present within ZnO capsules yields very high
42
value of transverse proton relaxivity when compared to the proton relaxivity value exhibited by the
individual CoFe2O4-ZnO core-shell nanoparticles.
Keywords: Bio-imaging; Nanoparticles; Graphene Oxide.
Development of an aluminium alloy for aerospace applications
at higher temperatures
Subodh Kumar
Department of Materials Engineering, Indian Institute of Science,
Bangalore – 560012, India
E-mail: [email protected]
The bulk of the commercial aircrafts are made of precipitation hardenable wrought Al alloys, since
they are light weight and possess adequate strength at room temperature. However, the
strengthening precipitates coarsen rapidly and lose strength at elevated temperatures. The highest
temperature at which wrought Al alloys can be used is 150°C for the Al-Cu based 2219 alloy. In our
group, the high temperature capability of this alloy has been raised to 200°C. This has been
achieved by adding small amounts of Sc and Mg to 2219 Al alloy and processing it in a different
way than the conventional direct chill casting followed by wrought processing and T8 temper
employed for this alloy. In the present investigation, the alloy was cast by suction casting in a
water-cooled copper mould followed by natural ageing and cold rolling. When this alloy is exposed
to 200°C temperature, Sc and Mg atomssegregate at the interface of the strengthening θ‟ (Al 2Cu)
precipitates making them stable at elevated temperatures. A few Ω precipitates are also formed,
which are stable at elevated temperatures. In addition, fine Al3(Sc,Zr) dispersoids are obtained,
which are stable at elevated temperatures. Thus, extremely good strength at room temperature, at
200°C, and at room temperature after 1000 hour exposure at 200°C are obtained for this alloy, that
have not been achieved for Al alloys so far. The presentation will highlight the salient feature of
microstructure at each stage that is responsible for such a high strength levels.
Rendering aluminium alloy 7010 resistant to stress corrosion cracking through
engineering microstructures
V. S. Raja
Department of Metallurgical Engineering and Materials Science
Indian Institute of Technology Bombay, Mumbai 400 076, India
E-mail: [email protected]
AA 7010 alloy is at the verge of being declared as obsolete due to growing stress corrosion cracking
(SCC) problems of aerospace structures made of this alloy. Concerted efforts are undertaken to
understand SCC mechanisms in order to impart SCC resistance. Though, it is generally suggested
that the SCC susceptibility of peakaged aluminium alloys is due to the extensive planar slip, our
study, on the contrary, has shown that SCC occurs through intergranular cracking assisted by
preferential electrochemical dissolution of grain boundary precipitates (GBPs) and making the grain
boundary chemistry highly relevant. The role of overaging on the SCC resistance of AA 7010
indeed has been found in enabling the GBPs not only nobler to the grains, by significantly
increasing their copper content, but also making them discontinuously spaced. The multistep
(over)aging employed, however, caused a significant loss in strength at the expense of attaining
SCC resistance, though the loss has been lesser than to that occurred in the conventional overaging
treatment. Microscopy study also showed that AA 7010 suffered extensive recystallization; another
43
reason for its susceptibility to SCC. To circumvent this problem, Sc addition was made to the alloy
to suppress recystallization and the alloy has been found to respond with significant improvement
for SCC resistance even at the peakaged condition! Sc has also been found to modify the
morphology as well as the distribution of the GBPs further enabling the alloy to resist SCC. The
work thus led us to believe that for an aluminium alloy to have high strength as well as resistance to
SCC, it must be tailored to have discontinuously located noble GBPs and populate grains with large
number fine precipitates. In order to obtain such microstructures, low temperature interrupted aging
was carried out to increase super saturation in order to have larger number of copper containing
precipitates. Such an aging, as expected, caused a steep raise in strength as well as ductility even in
3.5 wt.% NaCl solution.
Keywords: AA 7010, stress corrosion cracking, microstructures
Recent trends in grain boundary engineering
Satyam Suwas
Department of Materials Engineering,
Indian Institute of Science, Bangalore 560012, India
E-mail: [email protected]
The properties of polycrystalline materials are governed by their crystallographic texture and grain
boundaries. Grain boundary engineering is an approach designed to control the properties of
materials by controlling the grain boundary character distribution (GBCD), mainly by promoting a
high proportion of special grain boundaries in them. In this presentation, the background and the
basic concept of the grain boundary engineering (GBE) will be presented followed by a case study
on grain boundary engineering of a modified austenitic stainless steel to obtain a material with
enhanced properties. It was possible to obtain remarkably high fractions of CSL boundaries in
certain samples. The results of the micro-tensile tests indicate that the grain boundary engineered
samples exhibited higher ductility than the conventionally processed samples. The investigation
provides a detailed account of the approach to be adopted for GBE processing of this grade of steel.
Abnormal grain growth and mechanical behavior of
electro deposited nanocrystalline Ni and alloys
Sumit Chhangani and M.J.N.V. Prasad
Department of Metallurgical Engineering and Materials Science,
IIT Bombay, Mumbai-400 076, India
E-mail: [email protected]
In view of many potential applications, there has been considerable interest in producing
nanocrystalline materials with grain size less than 100 nm due to their exceptional physical and
mechanical properties. Electrodeposition is one of the promising single processing routes to
produce relatively bulk and dense nanocrystalline materials. Electrodeposited Ni has been model
nanomaterial for assessing microstructural stability and mechanical behavior at small length scales.
Microstructure instability during thermal cycling and mechanical deformation is one of the key
issues of nanocrystalline metals. It has been reported that upon heating nano-Ni exhibits two-stage
abnormal grain growth and however, reasons for this behavior are still debatable.Attempts have
been made to improve microstructure stability of nanocrystalline metals either by thermodynamic
approach or by kinetic way.
44
In the present investigation, the role of secondary elements such as S, Al, and Ti on microstructural
stability and mechanical characteristics of nano-Ni was studied. Differential scanning calorimetry
and electron microscopy were used to characterize stability of microstructure under thermal and
mechanical treatment. Tensile deformation behavior of nano-Ni as a function of secondary elements
concentration was studied. Significant effect of co-deposition of secondary atoms on texture
evolution during electrodepostion was noted. Upon annealing above 773 K, abnormal grains of
different sizes and fractions were observed. The abnormal grain populationwas found to be nonfaceted in nature and of largely {100} orientation withhigh fraction of Σ3 CSL boundaries.The
strength of nano-Ni increased initially but later both strength and ductility decreased with increasing
S, Al and Ti content.
Keywords: Nanocrystalline Ni; Electrodeposition; Abnormal grain growth; Tensile behavior; Grain
boundary engineering.
Effect of crystallographic texture on twinning during cyclic loading:
A case study on stainless steel and commercially pure titanium
S. Sinha, A. Ghosh and N. P. Gurao
Department of Materials Science and Engineering,
Indian Institute of Technology Kanpur,
Kanpur-208016, India
E-mail: [email protected]
Structural elements in aerospace, automotive and nuclear industry are routinely subjected to load
reversals and cyclic loading. It is therefore, paramount to understand the micro-mechanisms of
damage and failure in engineering materials. In addition to microstructural features like grain size,
type and volume fraction of phases and composition, preferred orientation of crystallites or texture
also plays an important role in determining mechanical properties of engineering materials. The
effect of crystallographic texture on mechanical properties in monotonic quasi-static and dynamic
loading has been studied extensively. However, the effect of crystallographic texture on cyclic
behaviour of crystalline materials is unexplored. The effect of load reversal is compounded in low
stacking fault energy face centre cubic and hexagonal close packed materials which deform by polar
twinning mechanism in addition to slip based deformation. In the present investigation, the effect of
crystallographic texture on twinning in face centre cubic stainless steel and hexagonal close packed
titanium has been studied as a function of texture in load reversal as well as stress and strain control
low cycle fatigue tests. This was achieved using cyclic testing on a servo-hydraulic universal testing
machine and in-situ stage in a scanning electron microscope with electron back scatter diffraction
facility. It is found that the Bauschinger strain, Bauschinger co-efficient as well as cyclic creep rate
and low cycle fatigue life in stainless steel and titanium is a strong function of texture with the
effect of texture being dominant in the latter case. It is proposed that the inherent anisotropy of the
hexagonal close packed titanium and significant contribution to strain from polar twinning
mechanisms contributes to augmenting the anisotropy in cyclic loading compared to monotonic
loading.
Keywords: Texture, cyclic loading, stainless steel, titanium, electron back scatter diffraction
45
Reactive spark plasma sintering process for synthesis of nanocrystalline ultra
high temperature ceramic based nanocomposites
Karthiselva N. S. and Srinivasa Rao Bakshi
Indian Institute of Technology Madras, Chennai, India 600036
E-mail: [email protected]
The borides of Zr and Ti have melting point above 3000 ºC and are known as ultra high temperature
ceramics (UHTC). They have unique properties such as low density, high elastic modulus (> 450
GPa), high hardness (> 25 GPa), low electrical resistivity (10-30x10-6 Ω.cm) and high thermal
conductivity (60-120 W.m-1K-1). They are potential candidate materials for applications such as
thermal protection of re-entry vehicles, rocket nozzles, armour materials, hypersonic vehicles and
crucibles for molten metals. SiC or MoSi2 has been widely added as a second phase to ZrB2 and
TiB2 to improve the oxidation resistance for most applications. Powder metallurgy is the only
method of fabrication of components. Achieving full density by pressureless sintering requires
temperatures above 2000ºC due to their low self diffusion coefficient. Application of hot pressing
can reduce the temperatures up to 1800ºC. However, grain growth is a problem which affects the
properties adversely. Recently, Spark Plasma Sintering (SPS) has been used successfully for
sintering of UHTC materials at lower temperatures of 1650ºC retaining fine grain sizes. We show
that by using Reactive Spark Plasma Sintering (RSPS) of ball milled elemental powder mixtures,
dense UHTC compacts can be prepared at temperatures as low as 1200ºC. Simultaneous synthesis
and densification is observed during RSPS. Moreover, grain size from sub-micron range are
obtained by RSPS. Addition of second phases such as carbon nanotubes, graphene nanoplatelets or
silicon carbide further reduce the grain size below 100 nm due to pinning of interfaces. The
properties of these compacts is found to be very high matching with that reported in literature.
Addition of second phases is observed to improve the indentation fracture toughness of the
composites. It is shown that RSPS can be an attractive method for sintering UHTC based
nanocomposites.
Keywords: Ultra high temperature ceramics, nanocomposite, nanocrystalline, reactive spark plasma
sintering, densification
Internal hydrogen embrittlement in Cr-Mn-N austenitic stainless steels and a
high entropy alloy
M. Phaniraj1, Jin-Yu Suh2, Seung-Jin Park3 and Heung Nam Han1
1
Department of Materials Science and Engineering,
Seoul National University, Seoul, South Korea
2
High Temperature Materials Center, Korea Institute of Science and Technology, Seoul
3
Department of AdvancedMetallic Materials, Korea Institute of Materials Science, Changwon
E-mail: [email protected]
Two sets of austenitic stainless steels each with similar stacking fault energy were chosen and
compared for internal hydrogen embrittlement. The two sets are 18Cr10Mn-0.3C0.3N and
18Cr10Mn-0.6N formed the first set and 18Cr10Mn-0.4N and commercially available 304 grade
Cr-Ni austenitic stainless steels. Thermal charging of hydrogen was carried out at 300C and
15MPa. Hydrogen content, tensile properties and microstructure of the steels were characterized.
Internal hydrogen degraded the ductility of all the steels. The embrittlement behavior will be
discussed based on the hydrogen content and martensite fraction present in the steels. High entropy
alloys are a promising new class of alloys that have caught the interest of the materials community.
46
The well-studied Cantor alloy i.e. Co20Cr20Fe20Mn20Ni20(at.%) will be tested for hydrogen
embrittlement and compared with austenitic steels under the same hydrogen charging conditions.
Keywords: Austenitic stainless steel, High Entropy Alloy, Hydrogen concentration, Embrittlement;
Ductility and Fracture
Phase transformations in Al-based quasicrystalline intermetallics during
mechanical milling
T. P. Yadav1, M. A. Shaz1, N. K. Mukhopadhyay2, R. S. Tiwari1 and O. N. Srivastava1
1
Centre of Advanced Studies, Department of Physics,
Banaras Hindu University, Varanasi-221005, India
2
Department of Metallurgical Engineering,
Indian Institute of Technology (BHU), Varanasi-221 005, India
E-mail: [email protected]
High energy mechanical milling has now become one of the important techniques for production of
metastable nano crystalline/quasicrystalline and amorphous phases. During the mechanical milling,
materials in powder form suffer severe high-energy impacts in the process of collisions of ball-toball and ball to vial of the grinding media which carried the phase formation and also sometimes
leads to several polymorphic phase transformations that are stabilized by the formation of huge
amount of structural and microstructural defects. The present study primarily focuses on research &
developments in the area of nanophase formation and phase transformation caused in
quasicrystalline materials arising during mechanical milling. We have chosen Al-Cu-Fe, Al-Pd-Mn
icosahedral and Al-Co-Ni, Al-Ni-Fe decagonal alloys systems for the investigation. The milling
was carried out in anattritor mill at 200-400 rpm for 1- 40 h with ball to powder ratio of 20:1 & 40:1
in hexane medium. The various isothermal annealing treatments were performed in vacuum and an
air ambience for 10, 20 and 40 h at 600 C. The X-ray diffraction (XRD), thermo gravimetric
analysis (TGA), differential thermal analysis (DTA) and transmission electron microscopy (TEM)
observation of milled and annealed sample confirmed the phase formation phase transformations.
The average crystallite size and strain have been calculated using Voigt function analysis of X-ray
diffraction line profiles. Further details regarding the evolution of nano phase and its various
characteristics will be presented.
Keywords: Quasicrystal, Intermetallics, mechanical milling, nano-materials
Metallic glass composites for defence applications
Bhaskar Majumdar
Defence Metallurgical Research Laboratory
Hyderabad 500 058, India
E-mail: [email protected]
DMRL has initiated activities for developing metallic glass composites in bulk forms for various
defence needs. Dual phase Fe(Co)-Si(Zr, Nb)-B-Cu based alloy systems, known as advanced soft
magnetic materials consisting of nanocrystalline phase embedded in an amorphous matrix are
potential candidates for devices where precision controlled energy supply with substantial weight
reduction is of important consideration. These materials are processed by preparing continous and
defect free amorphous ribbons through rapid solidification route followed by controlled heat
47
treatment.In this paper, some of the issues pertaining to the technological challenges in producing
quality amorphous ribbons are understood through the computer simulated results. Detailed
microstructural evolution and their correlation with the ultra soft magnetic properties will also be
discussed.
Another important activity for defence interest is the production of long rods made of bulk metallic
glass (BMG) and W composites. Since the processing of amorphous alloys in “bulk” shape still
remains a significant challenge, an alternative route has been adopted to produce composite
compacts where the dimensions are not restricted by the materials properties. In this process,
discs/rods are produced by compacting rapidly solidified powder within the undercooled liquid
regime of BMG. The fracture strength and strain of the compact with 99.5% relative density during
quasi static compression test was found to be 2.7 GPa and 0.1, respectively. The strain is higher
than that of the monolithic BMG of same composition. An interrupted compression experiment has
revealed the formation of numerous shear bands.
Structural origin of electrochemical activity in
transverse compositionally graded Li(Ni, Mn)xOycathodes
Joysurya Basu
Department of Metallurgical Engineering,
Indian Institute of Technology (BHU), Varanasi-221005, UP, India
E-mail: [email protected]
Diminishing fossil fuel resources and environmental concerns have provided the impetus for
research on energy generation and storage. Efficiency and life time of solid state batteries strongly
depends on the phases, microstructure and interfaces. Transverse compositionally graded Li(Ni,
Mn)xOy thin film cathodes have been investigated in the present work. The interface between
SrTiO3 and the oxide thin film is structurally sharp and no defect or reaction product is observed at
the interface. The presence of Li+ ions in the film can be confirmed by the characteristic energy-loss
edge in the EELS spectrum. The film is Ni-rich near the SrTiO3 interface and away from the
interface the distribution of Ni and Mn ions is almost homogeneous. In the diffusion coupled
multilayer thin film, the distribution of transition metal ions is almost homogeneous throughout the
film cross-section. The diffraction pattern from the film cannot be indexed unambiguously as
diffraction characteristics from rhombohedrally distorted LiNiO2 and cubic LiMn2O4 are almost
identical. By extensive phase contrast imaging and image simulation it has been determined that
ordered and disordered rhombohedral LiNiO2 and cubic LiMn2O4 spinel are present in the film. Due
to the epitaxial relationship and absolute coherence between the phases, grain boundaries are not
observed under normal imaging conditions. The epitaxial relationships are [112] SrTiO3‖ [112]LiMn2O4,
[112]SrTiO3‖ [1-10]LiNiO2, (111)SrTiO3‖ (111)LiMn2O4 and (111)SrTiO3‖ (006)LiNiO2. Disordering in the
LiNiO2 phase poisons its electrochemical activity. Furthermore, due to this epitaxial relationship,
cation layers in the LiNiO2 phase are not perpendicular on the substrate. This will introduce further
kinetic hindrance to the Li+ migration during biasing. In the spinel phase, tetrahedrally coordinated
Li+ ions diffuse randomly during biasing. These factors will kinetically deteriorate the
electrochemical activity of the cathode. In the presentation, atomistic origin of electrochemical
activity will be presented.
Keywords: Solid-state battery, Li(Ni, Mn)xOy, Thin film, Electron microscopy
48
Atomic scale study of Cu clustering and pseudo-homogeneous
nanocrystallization in Fe-Si based soft magnetic amorphous alloys
Pradeep Konda Gokuldoss
Materials Chemistry – RWTH Aachen University,
Kopernikusstr.10, 52074, Aachen, Germany
E-mail: [email protected]
Partially nanocrystalline FeSiNbBCu alloys with about 25 vol. % retained amorphous matrix are
used as transformer cores, chokes etc because of their excellent soft magnetic properties. Rapidly
solidified FeSiNbBCu amorphous ribbons upon annealing undergo nanocrystallization, wherein soft
magnetic Fe-Si nanocrystals are formed. Nanocrystallization of Fe-Si grains in these compounds is
kinetically governed by the size and density of Cu clusters that precede Fe-Si crystallization. In this
work we study the kinetics of Cu clustering and the subsequent Fe-Si nanocrystallization in an
amorphous Fe73.5Si15.5Cu1Nb3B7 alloy, when subjected to rapid (4s, 10s) and conventional (0.5h)
annealing by atom probe tomography (APT). Rapid annealing of as-prepared amorphous ribbons
results in the massive heterogeneous nucleation of Fe3Si nanocrystals with an estimated 60-100%
increase in their number densities than their conventionally annealed counterparts. Rapid annealing
when performed under uni-axial tensile stress (50 - 600 MPa), applied along the ribbon axis shows
strong creep induced anisotropy. Such anisotropy has its origin from the associated elongation of
Fe3Si nanocrystals induced during rapid stress annealing. The microstructural changes in terms of
the number density of Cu clusters and the resulting size difference of Fe-Si nanocrystals during the
two different annealing procedures investigated at multiple length scales employing, X-ray
diffraction, transmission electron microscopy, electron holography and APT will be presented.The
direct implications of these microstructural changes on the soft magnetic properties will be
discussed.
Keywords: Soft magnets, Nucleation, Atom probe tomography, Nanocrystals, Clustering.
49
Abstracts of Poster Presentations
50
Nano titanium dioxide incorporated phosphate coatings on low carbon steel for
corrosion protection
Pravin P. Deshpande and Vaibhav S. Kathavate
Department of Metallurgy and Materials Science
College of Engineering (COEP), Pune (M.S) - 411005.
E-mail: [email protected]
Phosphating is commercially used pre-treatment procedure before painting for the corrosion
protection of ferrous metals and alloys. However, dissolution of zinc during phosphating adversely
affects corrosion protection performance of subsequent paint system. Attempts are made to reduce
zinc dissolution and to enhance the performance of phosphate primer. It is anticipated that addition of
nano metal oxide particles may improve the performance of the primer. In present work, therefore,
optimization of the zinc phosphating electro deposition process variables- current density, deposition
time and quantity of nano titanium dioxide for addition in the bath was carried out using Taguchi
experimental design method and validated using electrochemical techniques. Results were analyzed
for surface responses in terms of coating resistance and corrosion rate using MINITAB 15 software.
Regression analysis was done and regression model was developed. Analysis of variance (ANOVA)
was carried out for predicting contribution of each process variable. Multi objective optimization was
done by calculating signal to noise ratio and rank of each process variable was predicted. The
corrosion protection performance of the coated low carbon steel was investigated in 3.5% NaCl
solution using Tafel polarization and electro chemical impedance spectroscopy.Tafel analysis reveals
that corrosion rate of nano TiO2 incorporated phosphate coated low carbon steel sample is ~ 1.38
mpy which is about four times less than that of uncoated low carbon steel ( ~ 8 mpy) in 3.5% NaCl
solution.
Keywords: nanomaterials, Corrosion, Carbon steel
Study of aging induced degradation of fracture resistance for alloy 617
Aditya Narayan Singh, A. Moitra, P. Bhaskar, G. Sasikala,
Arup Dasgupta and A.K. Bhaduri
Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research,
Kalpakkam, Tamil Nadu 603 102 India
E-mail: [email protected]
Alloy 617 is a candidate material for high temperature applications in both the thermal and nuclear
power plants. This material finds potential applications also in coal-fired power plants envisaged to
operate with high steam temperatures (973-1033 K) and high pressure (350-393 bar). To this end,
degradation of fracture resistance of this material in the operating conditions is a matter of concern
towards ensuring long term structural integrity of the components. In this work, the above
mentioned aspect has been investigated after long term aging at 750C by means of room
temperature Charpy impact tests. A reduction in impact energy by 55% after 1000 h aging has been
observed vis-a-vis the as received material. Aging up to 10,000 h has led to a degradation of
fracture energy up to 78%. A detailed investigation based on SEM and TEM results has been
carried out to understand the microstructural evolution that resulted in the degradation of fracture
energy. Fractographic observations, as shown by SEM studies, reveal that the fracture mode
changes from fibrous ductile for the un-aged material to intergranular for the aged material, the
extent of intergranular nature increases with increasing ageing time. This indicates grain boundary
embrittlement over long term aging. Analysis of the TEM micrographs along with selected area
51
diffraction (SAD) patterns for the samples aged at 750°C after 10,000h have revealed finely
dispersed γ‟ precipitates of size 30-40 nm, rich in Al and Ti. In addition, presence of Ni3Si of size
110-120 nm has been noticed. Along with γ‟ precipitates, extensive precipitation of M23C6 at the
grain boundaries have also been observed, which can be attributed to the grain boundary
embrittlement of this material after 10,000h of aging.
Keywords: Alloy 617, Impact, Aging, SEM, TEM
Spinodal Decomposition and ω Transformation in Binary V-Ti and Ternary
V-Ti-Cr Alloys
Chanchal Ghosh1, Joysurya Basu2, Divakar R1 and E Mohandas1
1
Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102,
2
Department of Metallurgical Engineering, IIT (BHU), Varanasi-221005
E-mail: [email protected]
Phase separation in an immiscible system could occur either through nucleation and growth or
spinodal decomposition mechanism. Both of these phenomena have their own characteristic
features. In the case of nucleation and growth, the mechanism depends on long range diffusion
process and hence the formation of precipitates with fixed composition and sharp incoherent
interface is expected. In contrary, spinodal decomposition is governed by the development and
growth of composition fluctuation wave and is governed by short range uphill diffusion. Naturally,
the interfaces between two such spinodally decomposed phases are expected to be coherent and
quite diffuse. Both of these mechanism can be distinguished by studying the early stages of the
phase separation and require detailed microstructural and microchemical investigations. Present
work deals with the phase separation and microstructural evolution studies of binary V-Ti and
ternary V-Ti-Cr alloys. Thermodynamic calculations based on the Miedema approach indicate the
presence of a miscibility gap for equiatomic V-Ti system and the convexity of the enthalpycomposition curve reduces with addition of Cr in the binary alloy. Alloys with pre determined
compositions have been synthesized in a vacuum arc melting unit and subsequently been heat
treated as per requirement. Z-contrast and phase contrast microscopy confirmed the phase
separation in both of these alloys. Energy filtered TEM microscopy confirmed the presence of a
chemical segregation in equiatomic V-Ti alloy where the modulation length in the as-melt condition
was measured as 4-5 nm. However, after heat treatment it is found that the fluctuation wave with
modulation length ~ 18-20 nm is getting stabilized in the alloy. The chemical segregation
propagates along <111> which is an elastically soft direction for bcc structured system. Moreover,
the quantitative and experimental phase contrast imaging along the phase separated domains
confirms the presence of deformed hexagonal zones of ω phase. The interface between the ω and
the bcc phase is almost coherent in nature showing a gradual change over 6-7 atomic layers for
complete structural transformation. Detailed microscopic investigation of spinodal decomposition
and structural imaging of nanostructured ω domains will be presented.
Keywords: Spinodal decomposition, ω transformation, HAADF, Energy-filtered TEM, Multislice
simulation
52
Corrosion behavior of TiZrHfNbTa high entropy alloy in nitric acid containing
halide ions
J. Jayaraj and U. Kamachi Mudali
Corrosion Science and Technology Group,
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603102, Tamil Nadu
E-mail: [email protected]
High-Entropy Alloys (HEAs) are usually composed of five or more elements with equimolar or
near equimolar elemental fractions when compared to conventional alloys containing one or two
principal elements, and they form single solid solution phase. HEAs exhibit excellent
microstructural stability at high temperature with better mechanical properties. In this work, the
TiZrHfNbTa alloy was developed and characterized for its corrosion properties in severe
environments such as boiling nitric acid, chlorinated nitric acid and fluorinated nitric acid. These
severe environments are encountered in the aqueous reprocessing of spent fuels of fast breeder
nuclear reactors. The passivation and corrosion mechanism of this TiZrHfNbTa alloy have been
discussed based on the Gibbs energies of formation of respective metal oxides, metal chlorides and
metal fluorides of the constituent element of the alloy. Further, SEM and XPS investigations were
carried out to understand the corrosion behavior of this alloy.
Keywords: TiZrHfNbTa, nitric acid, passivation, halide ions, dissolution
Evolution of crystallographic texture and microstructure in sputter deposited
NiMnGa thin films and their influence on magnetic properties
Amit Sharma1,2, S. Mohan2 and Satyam Suwas1
Department of materials Engineering, IISc, Bangalore 560012
2
Centre of Nano-science and Engineering, IISc, Bangalore 560012
1
E-mail: [email protected]
Shape memory alloys are the promising candidate materials for sensing and actuator based
applications. Amongst a variety of shape memory alloys, NiMnGa based magnetic shape memory
alloys are technologically most important owing to their superior properties such as large
recoverable strain, low field actuation and fast response. In the present study, a systematic study has
been performed to understand the effect of growth conditions and substrate selection on the texture,
microstructure and magnetic properties of sputter deposited NiMnGa thin films.
The film deposited in Zone T condition (500 °C) on Silicon (100) are polycrystalline with preferred
out of plane orientation. A gradual transition of crystallographic texture from (220) to (400) fiber
with increase in sputtering power has been observed and is correlated with the minimization of
surface and strain energies in the films. The higher grain size and better packing density in the film
deposited at higher sputtering power have led to superior magnetic properties in terms of lower
value saturation field and coercivity. The films deposited under Zone 2 condition (650 °C) on
silicon (100) substrate showed the development of a bi-axial texture with both out-of-plane and inplane preferred orientation. In-depth structural investigations reveal excellent crystal quality in
these films with rocking curve measurements. The cube on cube orientation relationship films and
the substrate further confirms the bi-axial alignment of unit cell due to imperfect epitaxial growth of
the film. Three levels of microstructural hierarchy and formation of epitaxial Ni-Si at the interface
are some of the key results from high resolution transmission electron microscopy studies. For the
53
first time, a four step phase transformation sequence „austenite → pre-martensite → martensite →
intermediate martensite‟ has been observed by temperature dependent magnetization and in-situ
high/low temperature X-ray diffraction studies.
NiMnGa films deposited on Al2O3 1120 substrate under Zone T condition shows bi-axially
oriented film with multiple variants. The TEM investigations reveals the presence of secondary
nano-twins formed by adaptive modulation within the primary martensitic twins. The presence of
six satellite spots within the main diffraction spots confirms the presence of seven modulated
orthorhombic martensite phase in the as-deposited film. Overall development of bi-axial texture and
epitaxial like growth in the films has been attributed to optimum growth conditions and suitable
selection of substrate with low lattice mismatch with the film (0.7%).
The last part of the work is dedicated to the epitaxially grown films on Al2O3 1120 and MgO
(100) substrates under Zone 2 condition. The minimization of lattice strain due to lower lattice
mismatch between film and substrate and higher mobility of ad-atoms led to the development of
such high quality films. The coexistence of non-modulated and seven modulated martensite phase
observed with TEM imaging provides a clear evidence of adaptive modulation of martensite in the
as-deposited film. The magnetic field induced reorientation of martensitic variants (MIR) has been
observed as an abrupt change in the slope of magnetic hysteresis.
Long term thermal stability of a new solar selective absorber coating
Atasi Dan1, Kamanio Chattopadhyay2, Harish C. Barshilia3 and Bikramjit Basu1,2
1
Materials Research Centre, Indian Institute of Science, Bangalore
2
Interdisciplinary Centre for Energy Research, Indian Institute of Science, Bangalore
3
Nanomaterials Research Laboratory, Surface Engineering Division, CSIR-National Aerospace
Laboratories, HAL Airport Road, Kodihalli, Bangalore
E-mail: [email protected]
The solar absorptance property of WAlN/WAlON/Al2O3-based coatings, deposited by DC/RF
magnetron sputteringon W coated stainless steel substrate was studied by measuring the reflectance
spectra in the wavelength range of 250-2500 nm.The effect of thermal annealing on the optical
properties, microstructure and morphology of the solar selective absorber coatings was investigated.
Annealing the coatings at 350°C for 450hrs in air did not show any significant change in the
spectral properties of the absorber coating indicating the excellent thermal stability of the
coating.The W layeracts asinfraredreflective layer and diffusion barrier on stainless steel substrate.
The top Al2O3 layer serves as dense shield to protect the under layers from oxidation in air. The
microstructural and compositional stability of the coatings at elevated structure was confirmed by
SEM and EDS analysis. The RMS roughness of the as-deposited and heat treated coatings,
determined from the AFM measurements, also validate that the coatings underwent insignificant
change after annealing.In summary, the present study indicates the potential application of
WAlN/WAlON/Al2O3-based selective coatings in mid temperature photo thermal conversion
systems.
Keywords: Sputtering, Solar selective absorber coating, Optical properties, Thermal stability
54
Isolation of pristine MXene from Nb4AlC3 MAX phase:
A first-principle study
Avanish Mishra1, Pooja Srivastava, Hiroshi Mizuseki2,
Kwang-Ryeol Lee2 and Abhishek K. Singh1
1
Materials Research Centre, Indian Institute of Science, Bangalore 560012, India.
2
Computational Science Research Center, Korea Institute of Science and Technology,
Seoul, 02792, Republic of Korea
E-mail: [email protected]
Recently a new, large family of two-dimensional (2D) early transition metal carbides and
carbonitrides, named MXenes, were synthesized from the MAX phase (Mn+1AXn, M = early
transition metal, A = group IIIA or IVA element and X = carbon and/or nitrogen). These layers are
isolated by selective etching of the A element from the MAX phases, wherein the layers are
connected by mix metallic, ionic, and covalent bonds. Nevertheless, synthesized MXenesheets are
always functionalized with F, OH and/or O atoms.Recent experimental studies, revealed that,this
uncontrolled, non-uniform and mixed functionalization, possesses serious challenges for its
practical applications such as thermoelectrics, hydrogenstorage, Li-ion batteries, etc.Therefore,
synthesis of pristine MXene is essential to realizeits true potential. Here by using first-principles
calculations, we perform a comprehensive study on the chemical transformation of MAX phase into
MXene sheets by inserting HF, alkali atoms and LiF in Nb4AlC3 MAX phase. Calculated bonddissociation energy (BDE) shows that the presence of HF in MAX phase always results in
functionalized MXene, as the binding of H with MXene is quite strong while that with F is weak.
Insertion of alkali atoms does not facilitate pristine MXene isolation due to the presence of
chemical bonds of almost equal strength. The BDE for Li–MXene and F–Al bonds in Nb4AlC3 after
LiF insertion is much smaller than that of other bonds formed between the MXene layers. However,
a lower kinetic barrier for the dissociation of the Li–MXene bond compared to that of F–Al
guarantees the dissociation of the Li–MXene bond under external perturbation leading to the
formation of pristine MXene. Ab initio molecular dynamics calculations capture these features and
show that at 500–650 K, the Li–MXene bond indeed breaks leaving a pristine MXene sheet behind.
Our results not only give insights into the mechanism for isolation of MXene but also provide a
general criterion for the selection of guest species, which can be used for the transformation of
MAX into pristine MXene layers.
Development of wrought Mg-Li based alloys
with improved strength and ductility
Chandra Shekhar Perugu, Subodh kumar and Satyam Suwas
Department of Materials Engineering,
Indian institute of Science, Bangalore – 560012 India
E-mail: [email protected]
Developing lightweight materials is a crucial to step on the path towards reducing energy
consumption in many industries, especially automotive and aerospace. Magnesium is a light weight
metal with a density of (1.74 g/cc) that is 23% of that of steel and 66% of that of Al, and hence has
tremendous potential to achieve energy efficiency. However, forming components with Magnesium
is difficult as it exhibits low ductility owing toits HCP crystal structure, and hence insufficient
number of deformation systems. Therefore, attempts have been made to develop magnesium alloys
by alloying with suitable elements. Lithium has been found to be a very appropriate alloying
element as it reduces the c/a ration of magnesium and alloys non basal slip systems to operate at
55
room temperature hence imparting ductility to the material. Although binary Mg-Li alloy are the
lightest structural materials amongst all Mg based alloy series, however limited strength and
corrosion resistance is a big problem to use these material for many applications. There are two
ways, in which these alloys can be strengthened, by further alloying addition which promotes
strength without deteriorating ductility, and by microstructural refinement by advanced casting
practices followed by severe plastic deformation. In this work, we are exploring squeeze casting of
Mg-Li based alloy and prior wrought processing (cold rolling), and also the possibility of severe
plastic deformation (ECAP, MAF) for different Mg-Li alloys. The preliminary results have
indicated that specific strength and ductility comparable to existing Mg alloy can be obtained in this
alloy system.
Keywords: Magnesium- lithium alloys, Squeeze casting, MAF (Multi axial forging), ECAP (Equal
channel angular pressing)
Formation of amorphous phase by supressing the binary intermetallic
compound with equiatomic substitution
S. Kashyap1 and B. S. Murty2
1
Department of Materials Engineering, Indian Institute of Science, Bangalore-560012.
2
Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras,
Chennai-600036.
E-mail: [email protected]
Metal-metal binary systems like Ni-Ti, Ni-Zr, Ni-Hf, Cu-Ti, Cu-Zr and Cu-Hf have been explored
earlier for their glass forming behavior. These systems commonly form MN, M2N and MN2 (where
M=Ni or Cu and N = Ti or Zr or Hf) type very stable crystalline intermetallic structures. Cantor and
coworkershave prepared amorphous structures in (TiZrHf)x(NiCu)90-xAl10, where the values of x
was varied between 20 to 70% discretely and successfully developed amorphous structure.
However, attempts to amorphize an exactly stoichiometric atomic proportion of any binary
intermetallic compound with equiatomic multicomponent substitutionare negligibly few till date. In
this work, we have shown that it is possible to destabilize the stoichiometric binary crystalline
intermetallic alloys into amorphous state by equiatomic substitution of multiple elements having
similar physical properties. For our study, we have chosen three intermetallic compounds Ni2Ti
(alloy 1), NiTi (alloy 2) and NiTi2 (alloy 3). Here we have substituted Ni with Ni-Cu and Ti with
Ti-Zr-Hf, respectively, in equiatomic proportions. Melt spinning techniquehas been utilized to
prepare the alloys. Thermal studies using differential scanning calorimetry (DSC) of alloy 1 and 2
show considerably high crystallizationtemperature (above 750 K) and high activation energy for
crystallization(1782 and 1312 kJ/mole, respectively), which indicate that the
amorphousstructureinthesemulticomponentalloysisrelativelystableagainstalloy3atthesameisothermal
annealingtemperature. X-ray diffraction and selected area diffraction (SAD) patterns confirm the
amorphous nature of as melt spun ribbons of all three alloys. High resolution electron microscopy
and electron diffraction investigations reveal the nucleation of nano size crystals of different
stoichiometric intermetallic compounds.
This work has been carried out in the collaboration with Prof. S. Ranganathan, Dept. of Materials
Engineering, IISc, Bangalore, Prof. Y. Yokoyama & Prof. A. Takeuchi, Institute of Materials
Research, Tohoku University, Sendai, Japan and C. Chattopadhyay of IIT Madras.
56
Grain boundary crystallography in polycrystalline yttria stabilized cubic
zirconia with varying densities and grain sizes
Maya K. Kini and Atul H. Chokshi
Department of Materials Engineering, Indian Institute of Science,
Bangalore, India – 560012
E-mail: [email protected]
Properties of grain boundaries such as grain boundary mobility, energy and diffusion are reported to
depend strongly on their crystallography. While studies on ceramic bicrystals with specific
misorientations have shown highly ordered structure at the grain boundary for certain coincidence
site lattice (CSL) misorientations, studies on dense polycrystalline ceramics have often shown the
significance of individual surface planes on either side of GB. In the present studyevolution of low
Σ misorientations and distribution of grain boundary plane normals were studied for yttria stabilized
cubic zirconia with varying densities and grain sizes.Orientation imaging microscopy(OIM) using
Electron Back Scattered Diffraction technique in scanning electron microscope was used combined
with a stereological approach to find likelihood of occurrence of different crystallographic planes.
GB plane distributions were found to be highly anisotropic for certain low Σ misorientations.
Fabrication and tuning the nanoporous channel in nanoporous membranes
derived using crystallization induced phase separation in polymeric blends
Maya Sharma1, Giridhar Madras2and Suryasarathi Bose1
Department of MaterialsEngineering, Indian Institute of Science,
Bangalore-560012, India
2
Department of Chemical Engineering, Indian Institute of Science,
Bangalore-560012, India
1
E-mail: [email protected]
In this work, a unique strategy has been adopted to tune the pore size through crystallization
induced phase separation in a model PVDF/PMMA (polyvinylidene fluoride/ poly methyl
methacrylate) blend system. PVDF/PMMA blend is a well-known UCST (upper critical solution
temperature) system which forms a miscible phase at higher temperature but phase separates upon
cooling, either by liquid-liquid phase separation (LLPS) or by solid-liquid separation through
crystallization of PVDF. There is always a competition between LLPS and crystalline-amorphous
melt phase transition during cooling. The blending of PVDF with PMMA (≤ 40% concentration)
leads to phase separation mainly driven by fast crystallization of PVDF and formation of three
distinct regions: PVDF crystallites, crystalline amorphous interphase and liquid-like amorphous
regions. During crystallization, the PMMA phase occupies the interlamellar and interspherulitic
regions of PVDF and there exists a clear boundary between ordered crystalline region and liquidlike amorphous region. As PMMA resides in the interlamellar and/or interspherulitic regions of
PVDF, depending on its composition in the blends, by selective etching of PMMA, nanoporous
channels can be designed. The pore sizes of membranes were tuned by changing the concentration
of PMMA in the blend. For instance, higher concentration of PMMA in the blend showed higher
pore size as compare to lower concentrations. Scanning electron microscopy (SEM) studies
revealed that the spherulites appeared more compact in 90/10 as compared to 70/30 and 60/40
PVDF/PMMA blends. As spherulites are more compact in 90/10 blends, the average pore size was
minimum in these set of blends. In view of this unique fabrication method, the obtained flux was
very high as compared to commercial available membranes. These membranes provide very high
flux with exceptional antibiofouling properties which can open new avenues in the existing
membrane industry.
57
High temperature and high strength aluminium alloys by
Dispersions of Al9Ni2 intermetallic compound
P. Padaikathan and K. Chattopadhyay
Department of Materials Engineering
Indian Institute of Science, Bangalore 560 012
E-mail: [email protected]
The commercially important aluminium alloys are classified by the nature of the alloying additions.
The existing alloys of 2219, 2618, 5086, and 7075 are important class of lightweight alloys plays
critical role in modern engineering applications. Despite having a series of useful aluminum alloys
for commercial applications, the increasing need of improved performance requires newer
development in particular for applications that require high strength at elevated temperatures and
performance at extreme environments. The technique of non-equilibrium solidification by suction
casting is becoming increasingly popular in the context of development of newer cast and powder
metallurgy processed alloys. The present work outlines a possible pathway to develop a set of
newer alloys, with small amount of alloying additions (<0.1%), that can retain reasonable strength
at high temperatures (200°C). Addition of Ni (0.10 at. %) to aluminium under moderate rapid
solidification condition that is achievable by suction casting produces fine dispersion of the
metastable compound of Al9Ni2. This has a monoclinic crystal structure. The microstructure at low
magnification exhibits a feathery morphology. Further additions of Sc and Zr as ternary and
quaternary promote precipitation hardening through the precipitation of Al3Sc and Al3(Sc,Zr)
intermetallic compounds having L12 ordered structure in the matrix of aluminium. The tensile yield
strength of the as cast alloy is 200MPa while after precipitation treatment, an improved yield
strength of 350-450MPa is observed. Thermal stability of the alloys in peak aged condition was
evaluated by exposure to 200C for 250h. The yield strengths of the alloys are unaffected by this
treatment, thus establishing the coarsening resistance of the dispersoids and precipitates.
Tin whisker growth from electro-deposited Sn films: Role of crystallographic
texture, stress and substrate
Piyush Jagtap
Department of Materials Engineering, Indian Institute of Science, Bangalore 560012
E-mail: [email protected]
Sn whiskering is a major long term reliability issue related to microelectronics. This issue is now
more exuberated due to complete removal of Pb from microelectronics, as minor alloying Sn with
Pb was the principle method for mitigating whiskering. The present work investigates the
fundamentals of Sn whiskering in terms of effects of crystallographic texture, stress, substrate and
simulated service conditions on whisker growth, and then proposes a benign and easily adaptable
method for whisker mitigation.Firstly, electro-deposition parameters, namely current density and
bath temperature, were systematically varied and their impact on the crystallographic texture, grain
size and coating thickness was studies. Out of possible simulated service conditions including
thermal cycling, whiskering rate was the highest and the minimum at 50 and 150 °C, respectively. It
was observed thatthe coatings withpredominantly low index planes, such as (100) and (110), were
more prone to whiskering. Consistently, micro-texture mapping also revealed that the low-index
planes, especially (100), surrounded by high index planes were the preferred whiskering site. This
can be attributed to the elastic anisotropy of Sn crystals, as the crystal plasticity based simulations
reveal that the above configuration is optimum for generating large stress gradient towards the soft
grains (i.e., (100)-planes), especially at triple points. In this context, stress measurement using
58
glancing angle x-ray diffraction and curvature measurement method revealed that residual stresses
become less compressive due to whiskering. Furthermore,externally applied stress and stress
gradient also enhanced whisker growth. Besides crystallographic texture and stress, whiskering is
also significantly dependent on the substrate on which Sn coating is placed, as the latter affects the
stress state in the Sn coatingdue to formation of intermetallic compounds at the interface. A brass
substrate is more prone to whiskering as compared to Cu due to excessive diffusion of Znand Cu
from brass from Sn coat. On the other hand, Ni interlayer between brass and Sn coating inhibits
diffusion of Cu, andZn into Sn coatings and alsoproduces intermetallic compounds which generate
less compressive stress in Sn coating, thereby reducing overall whiskering. In summary, Sn
whiskering can be mitigated if Sn coatings having high index planes can be deposited, by
manipulating electro-deposition condition of bath temperature and current density, on Cu substrate
with a thin layerof Ni in between.
Shear flow induced cellular morphological and functionality changes
in a microfluidic device
1
Sharmistha Naskar1, Bikramjit Basu1,2 and V. Kumaran1,3
Centre for Biosystem Sciences and Engineering, 2Materials Research Centre,
3
Department of Chemical Engineering
Indian Institute of Science, Bangalore, 560012, India
E-mail: [email protected]
Conventional cell culture cannot mimic the in vivo microenvironment. The aim of our study is to
unravel the cellular functionality in vitro, with a very close resemblance of in vivo scenarios.We
have chosen two cell-types C2C12 for this purpose and cultured them in a confined manner within
the microchannels along with flow condition. C2C12 cells exhibited alteration with cell and nuclear
elongation. Application of shear of about 1mPa on the C2C12 cells had differentiated them into
myotubes. Moreover, the cells had manifested change in nuclear morphology in response to the
applied shear stress. In order to perform this experiment, acrylic sheets were cut through for
preparing the channels of desirable dimension (about 2mm) using a laser cutter instrument
(universal laser system).The cells were stained with myotube markers like myogenin and MyoD to
investigate the differentiation phenomenon. There is a distinct graded expression of these
biomarkers depending upon the spatial location within the channel and amount of shear stress
applicable at that region. Concomitantly, the transmitted shear alters the mechanical configuration
of focal adhesion-associated proteins probably through tyrosine kinase activity, yielding increased
tyrosine phosphorylation of an intermediate protein. Some researchers have found that Nesprin-3
with its interaction with Vimentin and Plectrin plays a role for change in nuclear morphology in
response to shear.The end result of this confinement with perfusion is a morphological steady state
configuration with surface shear gradients. This study demonstrates not only that mouse myoblast
cells are sensitive to fluid flow shear forces, but also that confinement within the small space results
in phenotypical changes. It can be concluded that flow-induced shear forces for cell act as important
biological stimuli in the generating the decision-making molecular signaling. Also, constituting in
vivo like microenvironment provided within the micro-bioreactor can represent the intra-visceral
consequences in a better way. Nevertheless, shear stressed induced cell migration can be studied
which will be an achievement towards the feat of unraveling the underneath molecular mechanism
of developmental process and cancer metastasis.
Keywords: Microfluidic Bioreactor, Shear stress, laser cutting, Immunofluorescence
59
3D powder printing of resorbable calcium phosphate scaffold for
lowload-bearing application using novel phytic acid binder
Sourav Mandal1, Susanne Christ2, Uwe Gbureck2 and Bikramjit Basu1
1
Laboratory for Biomaterials, Materials Research Centre,
Indian Institute of Science, Bangalore - 560012, India
2
Department for Functional Materials in Medicine and Dentistry,
University of Würzburg, Pleicherwall 2, 97070, Würzburg
E-mail: [email protected]
To fabricate calcium phosphate (CaP) based scaffolds for bone tissue engineering using 3D powder
printing, physical and chemical adhesion are the two main approaches for binder-powder
interaction. Chemical adhesion has its advantages e.g. low temperature fabrication avoiding
sintering, possibility of incorporation of drugs or growth factors, etc. Most these studies using
chemical adhesion utilizes phosphoric acid as binder but the drawback is that it induces HA
formation. This makes the scaffolds non-resorbable due to presence of HA on the surface, which
has very low solubility in physiological pH.
3D powder printing technology have recently been found extensive use in these kind of application
and there is a constant requirement of new binder development to address these specific
requirements. In our study, we have used phytic acid as the novel binder to successfully fabricate
the scaffolds using two powders (TTCP and a Na, K substituted CaP)with designed macropores of
500 µm size and reasonable mechanical strength. The printing parameters, binder composition and
post hardening schedule has been optimized to yield the scaffold with best mechanical and
structural properties achievable. We have also demonstrated that, the use of phytic acid as binder
and as post hardening solution could restrict the formation of HA after 7 days of immersion of the
scaffolds in PBS. From XRD analysis, the formation of a chelate between the Ca present in the CaP
and phytic acid is speculated and believed to be the inhibitory factor in HA formation. The use of
micro computed tomography confirmed that the final scaffold in comparison to the CAD model,had
deviation less than 0.2 mm and also the bulk 3D porous microstructure was visualized and
quantified. The full fabrication technique starting from raw powder to final scaffold was carried out
at room temperature so that advantages in low temperaturefabrication can be availed. In conclusion,
we have demonstrated the use of a new binder, which can be used in 3D powder printing of CaPs
when resorbablity of the scaffold is the primary criterion.
Keywords: 3D scaffold, calcium phosphate, tomography.
Three dimensional inkjet printing of Ti-6Al-4V based scaffolds with
homogeneous and gradient porosity
Srimanta Barui1, Alok Kumar1, Sourav Mandal1 and Bikramjit Basu1,2
1
Laboratory for Biomaterials, Materials Research Centre,
Indian Institute of Science, Bangalore, India
2
Centre for Biosystems Science and Engineering,
Indian Institute of Science, Bangalore, India
E-mail: [email protected]
Metallic implants are used in load bearing orthopedic applications due to high fracture toughness
and strength. However, the application is limited due to higher elastic modulus of metallic implant
than host bone. This leads to bone resorption due to stress shielding effect, which reduces implant
60
stability. Moreover, angiogenesis and osteogenesis depend on porous architecture. While addressing
such twin requirements, the present study demonstrates a new low temperature additive
manufacturing based processing strategy to fabricate Ti-6Al-4V scaffolds with designed porosity
using inkjet-based 3D powder printing (3DPP). A novel maltodextrin-based adhesive binder
(aqueous) was prepared and the physico-chemical parameters such as pH, viscosity, and surface
tension were optimized for drop-on-demand (DOD) based thermal inkjet printing. Micro-computed
tomography (micro-CT) of sintered scaffolds revealed a 57 vol.% total porosity in homogeneously
porous scaffold and 45 vol% in the gradient porous scaffold with 99% micropores interconnectivity.
The uniaxial compression response revealed more progressive failure in homogeneously porous
scaffold compared to gradient porous scaffolds. The compressive strengths of homogeneously
porous and gradient porous scaffolds were ~47 MPa and ~90 MPa, respectively. A higher elastic
modulus was recorded with gradient porous scaffolds (~3 GPa) than the homogenously porous
scaffolds (~2 GPa). An attempt has been made to rationalise the obtained properties in the backdrop
of the porosity architecture and microstructural phase assemblage. While comparing with the prior
literature reports, the present work, for the first time, establishes „direct powder printing
methodology‟ of Ti-6Al-4V porous scaffolds with biomedically relevant microstructural and
mechanical properties.
Intriguing aspects of growth, structure and properties of
molecular-scale Au nanowires
Subhajit Kundu and N. Ravishankar
Materials Research Centre, Indian Institute of Science,
Bangalore, India – 560012
E-mail id: [email protected]
Growing anisotropic nanostructures of high symmetry materials is a challenging task owing to the
symmetry breaking that is required. We have developed a simple wet chemical method by which
ultrathin (< 2 nm diameter) Au nanowires could be grown in the solution phase. The details of the
mechanism of these wires will be presented using electron microscopy as the principal supporting
tool. Methods to grow these wires on substrates and directly between pre-patterned contact pads
will be shown. This enables the direct measurement of electrical transport through these wires. We
find an unexpected insulating behaviour in these wires with the resistivity decreasing as a function
of the temperature of measurement. The implications of this observation will be discussed. Some
intriguing results on the atomic structure of these nanowires where we find modulations of atomic
planes normal to the growth directions will be presented. Some interesting applications of these
ultrathin metal nanowires in sensing and catalysis also will also be shown.
Phase transformation and biocompatibility study of
metastable β Ti-Nb-Sn alloy for orthopedic applications
Sumit Bahl, Satyam Suwas and Kaushik Chatterjee
Department of Materials Engineering,
Indian Institute of Science, Bangalore 560012 India
Email: [email protected]
Metastable β Ti alloys are regarded as future materials for use in orthopedic implants. The
characteristics like non-toxic alloying elements, low elastic modulus, high corrosion resistance and
high specific strength makes β Ti alloys a viable option for orthopedic implants. The aim of this
61
investigation is to evaluate phase stability and biocompatibility of a new Ti-32Nb-2Sn alloy
proposed for orthopedic application. The mechanisms of precipitate nucleation, growth,
strengthening and softening are discussed. The nucleation of α phase during aging treatment is
found to follow classical nucleation theory, in contrast to literature where pseudo spinodal
mechanism or indirect modes of precipitation are proposed for other β Ti alloys. The partitioning of
alloying elements between matrix and precipitate, as characterized by TEM based EDS mapping
was found to be dependent on aging temperature. The coarsening of precipitates is found to likely
occur by mechanism of coalescence. An interesting age-softening behaviour was observed after
aging at high temperature which has been correlated to inhomogeneous composition of the matrix.
The alloy is found to be biocompatible as the hMSC (human mesenchymal stem cell) attachment
and proliferation is same as pure Titanium. The results of hMSC differentiation are also presented
and discussed.
Phase-field study of the electric current induced void evolution and
grain-boundary grooving
Supriyo Chakraborty and Abhik Choudhury
Department of Materials Engineering, Indian Institute of Science,
Bangalore, India - 560012.
E-mail: [email protected]
A novel multi-phase field model has been developed to understand the void migration and growth
in interconnects due to electromigration. Using this model we successfully simulate the
characteristics of void morphologies. For low current densities the growing voids retain their shape,
while for higher current densities, the voids get elongated. The calculated velocity of void migration
and their volume have been found to linearly vary with the applied potential difference, which
agrees also with theoretical predictions. Subsequently, we investigate the influence of anisotropy in
surface energy and surface diffusivity on the void morphologies. Thereafter, we extend our study to
the more realistic situation of polycrystalline interconnects, where firstly we simulate grainboundary grooving and migration under electromigration conditions in 2D, for a system of two
grains. Here, we also compare with analytical theories for grain-boundary grooving without
electromigration. Finally, we present grooving studies and hillock formation in 3D between
multiple grains. We investigate the effect of temperature gradient on mass transport and couple it
with the elctromigration, we simulate the higher rate of mass transport from the cathode side and an
anomalous back flow of atoms from anode side.
Multi-phase flow model of a blast furnace
Smita Kamble, Vinci Mojamdar and Govind S. Gupta
Department of Materials Engineering
Indian Institute of Science, Bangalore 560012
E-mail: [email protected]
Blast furnace is a complex multiphase (gas, solid, fine and liquid) flow reactor. Stable blast furnace
operation is necessary to achieve high productivity. To accomplish this, complete knowledge of
mass, momentum and heat transfer inside the furnace is required. Many researchers have done lot of
work towards the understanding of blast furnace operation. Our group has done work towards the
understanding of the physics of various phenomena occurring inside the blast furnace. This involves
determining the correlation to predict the raceway size. Raceway is a cavity which is formed when
hot blast air is injected in to the blast furnace. It is a very important phenomenonin a blast furnace
62
as the shape and size of raceway determines the productivity of a blast furnace. Also, raceway
hysteresis phenomena have been studied via experiments. It has been observed that decreasing gas
velocity condition represents the blast furnace situation more accurately than increasing gas velocity
condition. Many theoretical studies have also been done to predict the raceway shape & size, gas
flow in a packed bed, liquid(non-wetting) flow behaviour in a packed bed, gas-fine flow behaviour
in a packed bed. To study the gas and fine flow behaviour continuum approach has been used. Solid
flow behaviour has been studied using discrete element model (DEM) and discrete approach has
been used to study the non-wetting liquid flow behaviour inside the packed bed.
Processing and characterization of AlCoCrFeNi and AlCoCrFeNiMn
high entropy alloys (HEAs) via mechanical alloying
Vikas Shivam and N. K. Mukhopadhyay
Department of Metallurgical Engineering,
Indian Institute of Technology (BHU),
Varanasi-221005, India
E-mail: [email protected]
A high entropy alloy (HEA) is defined as an alloy system, composed of five or more kinds of
principal elements in an equimolar or nearly equimolar ratio, with a small difference in atomic radii
(<15%) and concentration of each element varying from 5 to 35 at% These HEAs possess excellent
properties like higher hardness, strength as well as improved wear, oxidation, good corrosion
resistance and other functional properties.
In this work, AlCoCrFeNi and AlCoCrFeNiMn high-entropy alloys (HEAs) were prepared by
mechanical alloying in a high energy planetary ball mill (Retsch) PM400 up to 35 hours. Structural
and microstructural characterizations were carried out by X-ray diffraction (XRD), scanning
electron microscopy (SEM) and transmission electron microscopy (TEM TECNAI G2-operated at
200 KV) techniques. The NETZSCH DSC 404F apparatus was used to check the thermal stability
of the alloy powder at a constant heating rate of 40.0(K/min). In both the alloy systems, bodycentered cubic (bcc) structure with lattice parameter of 2.94 and 2.95 Å was observed. It should be
noted that, both the alloy systems are having BCC structure, elements like Fe and Cr are stronger
elements which are more open structure with high melting point. Micro hardness of AlCoCrFeNi
and AlCoCrFeNiMn high entropy alloy sintered at 900°C was 905 and 910 HV respectively.
Attempts will be made to find out the yield strength and other mechanical properties of both the
alloy systems.
Keywords: High entropy alloy, Mechanical alloying, Characterization of Phases, Mechanical
properties.
Microstructure and mechanical properties of Sn reinforced
Al–Cu–Fe quasicrystalline matrix composite
Yagnesh Shadangi, Kausik Chattopadhyay and N. K. Mukhopadhyay
Department of Metallurgical Engineering
Indian Institute of Technology (Banaras Hindu University),
Varanasi – 221005, India
E-mail: [email protected]
The quasicrystals are relatively new class of materials which belong to a family of aperiodic
intermetallics, and possess high hardness, excellent wear resistance, low coefficient of friction, low
63
thermal and electrical conductivity accompanied with good corrosion resistance with inherent
brittleness and low fracture toughness. Soft phases are found to overcome the inherent brittleness
and low fracture toughness of Al-Cu-Fe quasicrystal.
The Al62.5Cu25Fe12.5 quasicrystalline matrix reinforced with 10, 20 and 30 volume fraction of Sn
was synthesised by high energy ball miling. The milling was carried out in a PM 400 Retsch ball
mill at speed of 200 rpm for 10, 20, 30, 40 h with a ball to powder ratio of 10:1 under controlled
atmosphere. The milled powder was hot pressed at 800 oC in a 100 ton press. The consolidated
pellets werecharacterized by optical microscopy, scanning electron microscopy, x–ray diffraction
techniques. The mechanical properties were evaluated through microindentation and compressive
testing techniques. The hardness and fracture toughness of as-annealed Al62.5Cu25Fe12.5
quasicrystalline matrix was found to be 10.87 GPa and 1.58 ± 0.27 MPa.√m respectively. The
hardness of composites was found to decrease with volume fraction of Sn whereas the fracture
toughness was found to increase appreciably. The increase in fracture toughness was attributed to
inhibition of crack propagation by Sn particles. The present study provides an insight into the
mechanisms of phase and microstructural evolutions during MA of the Sn reinforced
Al62.5Cu25Fe12.5 quasicrystalline nano- composite and their consequent effects on mechanical
properties.
Keywords: Mechanical alloying; Quasicrystal; Sn; Microindentation; Compressive strength.
Application of secondary aging for rising environmentally assisted
cracking resistance of AA 7010
M. Ajay Krishnan and V. S. Raja
Department of Metallurgical Engineering and Materials Science
Indian Institute of Technology Bombay, Mumbai, India 400076
E-mail: [email protected]
Aluminum alloys of 7xxx series have found extensive applications as structural materials in
aerospace industries as they have high specific strength. As there is a sustained demand to raise
high specific strength of these alloys there has been continuous evolution in the grades and tempers
of these aluminum alloys to meet this need. However, so far a compromise has been made on usable
strength levels of alloys in order to avoid environmentally assisted cracking (EAC). To address this
issue, this work focuses on a modified temper condition in comparison with the conventional
tempers especially to promote the use of AA 7010 despite its inherent EAC failures. The influence
of the modified temper on the EAC behavior of AA 7010 was evaluated using slow strain rate tests
(SSRT) in 3.5 wt. % NaCl. The secondary aged alloy surpassed the conventional tempers in
providing not only high strength levels but also superior EAC resistance in 3.5 wt.% NaCl solution.
Secondary aged alloy showed an increment of ~10% in strength levels (UTS) and the elongation
(%) increased from 12% to 14% with respect to over aged temper in 3.5 wt% NaCl. Transmission
electron micrographs of differently heat treated specimens revealed the morphological and chemical
changes associated with the modified temper responsible for the improvement in the EAC
resistance as well as the strength of the alloy.
Keywords: Aluminum alloys, Stress corrosion cracking, modified temper
64
Hydrogen evolution on magnesium during anodic polarization:
A consequence of enrichment of noble alloying elements
Poorwa Gore1,2,3, Nick Birbilis2 and V. S. Raja3
1
IITB-Monash Research Academy, India
2
Department of Materials Engineering, Monash University, Vic. 3800, Australia
3
Department of Metallurgical Engineering and Materials Science,
Indian Institute of Technology Bombay, Mumbai 400076, India
E-mail: [email protected]
Electrochemical corrosion tests were carried out on pure Mg and custom binary alloys Mg-0.1wt.%
Au and Mg-0.1wt.% In. Both these alloyed elements are noble to magnesium and they also differ in
their intrinsic hydrogen evolution kinetics, through their io,HER values. At the potentials where
magnesium is actively dissolving, these alloying elements are still in their cathodic regimes. These
binary alloys were designed to envisage the effect of incongruent dissolution and consequential
enrichment of surface with the alloying elements on the anodic hydrogen evolution rates and
cathodic kinetics. Potentiodynamic polarization, galvanostatic polarization and mass loss tests were
carried out on them in 0.1M NaCl solution. Mass loss tests and galvanostatic polarization tests were
accompanied by hydrogen collection. It was observed that the two alloys with the same amount of
alloying elements show different rates of hydrogen evolution. The Mg-Au alloy shows the highest
rate of hydrogen evolution followed by Mg-In and then pure Mg at OCP as well as at an applied
anodic current density of 5mA/cm2. It was concluded that the anodic hydrogen evolution rates on
corroding magnesium surface are dependent on the characteristic i0,HER values of these cathodic
alloying elements.
Keywords: Magnesium, Hydrogen evolution, Cathodic Kinetics, Anodic Dissolution, Enrichment
Green synthesis and stability of pristine free standing silver metal nanoparticles
by cryomilling
Nirmal Kumar and Krishanu Biswas
Material Science and Engineering Indian Institute of Technology, Kanpur
E-mail: [email protected]
Nano materials have received great attention due to their wonder properties at nano regime. Many
methods came in lime light in last few decades due to increasing demand of nano materials as well
as alert to protect our environment from toxic substances. The widely accepted syntheses for easily
preparation of metal nanoparticles are chemical routes in which hazard chemicals being used.
Recently, researchers have serious attempts to develop the eco-friendly method to prepare
nanoparticles. In the concern of environment, green synthesis of metal nanoparticles are highly
desirable. In this paper green synthesis of pristine free standing Ag metal nanoparticles has been
synthesised by sophisticated method cryomilling. This cryomilling is cost effective rapid and
mechanical method to prepare metal nanoparticles in which the powder were milled below
temperature -150±10 °C under argon gas environment. The 5-8 nm particles size was achieved
after milling 6 hours 30 minutes, which are found to be highly stable at higher temperature. The
most of the methods to prepare Ag nanoparticles are wet chemical routes in which, hazards
chemicals being used and mixed with surfactant for stabilization of the particles. The presences of
surfactant sacrifice the purity and the native property of the particles. In the cryomilling, possible
contaminations during synthesis such as oxidation of particles surface, nitridation, and debris from
milling tool have been estimated by EPMA and ICP-OES analysis. The Ag metal nanopowder was
characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope
to confirm composition morphology and size of the particles.
Keywords: Pristine, Cold welds, Free Standing, Metal, Ag.
65
Bulk preparation of graphene: Synthesis and application
Shikhar Misra and Krishanu Biswas
Indian Institute of Technology, Kanpur
E-mail: [email protected]
Graphene is a single layer of graphite with carbon atoms arranged in a hexagonal 2D lattice.
Producing it cheaply and on a large scale is a key challenge for making it useful. In the present
thesis, a domestic kitchen blender was used to produce graphene from the mixture of graphite
dispersed in N-Methyl-2-pyrrolidone (NMP). The formation of graphene was confirmed using
Raman spectroscopy, X-Ray Diffraction and TEM study. Then, using graphene and graphene oxide
as starting material, silver nanoparticles were decorated on it via chemical route. All the samples
were structurally and optically characterized. Silver nanoparticles were successfully incorporated in
graphene, which was confirmed by X-Ray Diffraction (XRD), Scanning Electron Microscopy
(SEM), Transmission Electron Microscopy (TEM) and UV-vis spectroscopy. Since silver particles
act as an anti-bacterial agent, graphene-silver hybrids can be used as an effective water filter.
Turbulence has been found to be a key factor which causes shear exfoliation of graphite to form
graphene. Hence, modelling of fluid flow in the kitchen blender was done in ANSYS Fluent and
geometry of the blender was found to have a clear impact on the turbulence generation inside the
blender. Fluoride contamination in groundwater is a big concern in developing countries especially
India. Graphene and graphene oxide are well known materials in water remediation field and are
capable of adsorbing heavy-metal ions. So, we wanted to check the adsorption of fluoride from
synthetic groundwater using graphene and graphene oxide as adsorbents. Batch adsorption
experiments were performed for this purpose. The fluoride uptake capacity of both graphene and
graphene oxide was found out to be  10%. Qualitative analysis was also done using a cold
beverage and graphene oxide was found to be effective in adsorbing the color of the drink.
Keywords: graphene, liquid phase exfoliation, fluoride adsorption, batch experiments, modeling
New insights for modeling strain hardening behaviour in
age hardenable Al alloys
Sumeet Mishra, Manasij Yadava, Kaustubh Kulkarni and N. P. Gurao
Department of Materials Science and Engineering,
Indian Institute of Technology, Kanpur Kalyanpur,
Kanpur – 208016, India
E-mail: [email protected]
In the present investigation, work hardening behaviour of Al-Mg-Si alloys in different temper viz.
solutionized, under-aged, peak-aged and over-aged condition have been analyzed in the framework
of both one internal variable approach and two internal variable approach. The one internal variable
approach taking forest dislocation density as the only internal state variable fails to describe the
transient flow at the onset of plastic deformation and the overall work hardening behaviour. The
different variants of one parameter model taking into account the effect of grain boundaries,
incoherent precipitates, coherent precipitates and solute atoms also fail to give an accurate
description of work hardening behaviour. However, the analysis based on two internal variable
approach taking into account both forest dislocation density and mobile dislocation density as the
internal state variables appropriately describes all the observable stages in the strain hardening
curve. The work hardening parameters obtained from two internal variable approach provides better
insights into the physical phenomena controlling the deformation behaviour of materials.
Keywords: Work hardening, Forest dislocation, Mobile dislocation
66
Microstructure, mechanical and oxidation properties of
Ti-Al-Ni-Cr-Co-Fe based multi-component alloys
R. Anand Sekhar1, Niraj Nayan2, G. Phanikumar1 and Srinivasa R. Bakshi1
1
Department of Metallurgical and Materials Engineering,
Indian Institute of Technology, Madras, Chennai – 600036, India
2
Materials and Mechanical Entity, Vikram Sarabhai Space Centre, Trivandrum
E-mail: [email protected]
Alloying can make drastic changes in mechanical and chemical properties. In conventional alloys,
addition of other elements is usually restricted to only small amounts. High Entropy Alloys having
generally more than five elements in equiatomic compositions show an enormous increase in
configurational entropy making it thermally stable even at high temperatures. In the present work,
the microstructural aspects and mechanical properties of seven HEAs with nominal compositions
TiAlNiCr, TiAlNiCrCo, TiAlNiCrFe, TiAlNiCrCoFe, TiAlNiCo, TiAlNiFe and TiAlNiCoFe have
been studied. The high entropy alloys were prepared by ball milling followed by Spark Plasma
Sintering (SPS). These alloy powders show two BCC phases after 8 hours of milling.
Microstructural characterization was done using optical microscope, XRD, SEM and TEM.
Segregation of phases were observed in alloys with Cr. The other three alloys prepared without Cr
shows two BCC phases with one major and a minor one and also the Cr segregation was avoided.
Micro hardness tests done on the alloys reveal that all the alloys exhibit good hardness value with
TiAlNiCrCoFe alloy exhibiting highest value close to 1000 HV. Room temperature compressive
strength was measured for all the alloys at a strain rate of 10-3 s-1 using a Zwick/Roell Z100
mechanical testing machine. All the alloys show good compressive strength above 1 GPa at room
temperature. Effect of phase evolution on the mechanical properties was studied using nanoindentation. Elastic modulus and hardness of the phases were measured from load the displacement
curves and the contribution of each phase on the mechanical property was studied. Oxidation
studies were conducted for the alloys at 800 °C, 900 °C and 1000 °and the effect of composition is
presented.
Keywords: High Entropy Alloy, Equi-atomic, Oxidation
Implication of grain boundary engineering on
high temperature hot corrosion of alloy 617
K. Deepak1, Sumantra Mandal2, C. N. Athreya1, Dong-Ik Kim3,
B. de Boer4 and V.Subramanya Sarma1
1
Dept.of Metallurgical and Materials Engg., Indian Institute of Technology, Madras, India
2
Dept. of Metallurgical and Materials Engg., Indian Institute of Technology, Kharagpur, India
3
Korea Institute of Science and Technology, Seoul, Republic of Korea
4
VDM Metals GmbH, Werdohl, Germany
E-mail: [email protected]
Grain boundary engineering (GBE) has been shown to be aneffective approach to improve the
properties and performanceof bulk polycrystalline materials. The GBE involves manipulation of
grain boundary character distribution to enhance thefraction of special boundaries in the
microstructure and this isoften realized by designing optimized thermo-mechanical processing
schedule. Recent results haveindicated that only a subset of lowCSLs are special.In spite of this
assumption, GBE approach has been shown to beeffective in enhancing the properties in a variety
of low-to-medium stacking fault energy materials. This is essentially dueto the fact that these
materials exhibit prolific multiple twinningduring GBE-type thermo-mechanical processing leading
to higherfraction of „special‟ 3 boundaries terminating on low-index plane. In the present paper,
67
we discuss the role of grain boundary engineering (GBE) on high-temperature hot corrosion
behavior of alloy 617. High temperature corrosion was evaluated by exposing both the as-received
(AR) and GBE specimens in a salt-mixture of (75%Na2SO4+ 20% NaCl + 5% V2O5) at 1273K for
24h. The AR specimen having continuous network of randomhigh angle grain boundaries (HAGBs)
has undergone hot corrosion and substantial depletion/segregationof alloying elements through the
entire cross section. The GBE specimen exhibited significantly reducedhot corrosion and
depletion/segregation of alloying elements. This is attributed to the high fraction of3-CSL triple
junctions which break the percolation in the random HAGBs network.
Keywords: superalloys, EBSD, grain boundary engineering, high temperature corrosion,
segregation
Phase prediction studies in AlCoCrFeNi high entropy alloy
Guruvidyathri K, Ravikirana, Mayur Vaidya, Hari Kumar K.C and B. S. Murty
Department of Metallurgical and Materials Engineering
Indian Institute of Technology Madras, Chennai 600036
E-mail: [email protected]
The present paper reports phase predictionin AlCoCrFeNi high entropy alloy by CALPHAD
(CALculaion of PHAse Diagram) technique usingTCHEA1Gibbs energy database in combination
with Thermo-Calc software. Phase fraction as a function of temperature was calculated.
Composition of phases at various temperatures was also calculated. Predicted primary solidifying
phases are of BCC and B2 structure. As the temperature decreases there is a temperature range of
over which a FCC is predicted to appear. Validation of these Calphad results were attempted in ascast and heat treated AlCoCrFeNi alloy. The alloy was prepared throughvacuum arc melting.
Subsequently, the cast samples were heat treated at temperatures of 600-1325°Cfor 1 day.
Characterization was done usingXRD, SEM/EDS and TEM.The experimental results are discussed
in the light of the CALPHAD calculations to understand the phase evolution in this high entropy
alloy.
Keywords: High entropy alloys, Multiprinciple element alloys, CALPHAD, AlCoCrFeNi
Phase evolution in nanocrystalline AlCoCrFeNi by varying sequence of
elemental additions: Novel approach to alloy synthesis using
mechanical alloying
Mayur Vaidya, Anil Prasad, Abhinav Parakh and B. S. Murty
Department of Metallurgical and Materials Engineering,
Indian Institute of Technology, Madras, Chennai – 600036, India
E-mail: [email protected]
The conventional way to form a multicomponent alloy, by any method, involves mixing individual
elements in required proportion. Phase formation, therefore, is governed by inherent
thermodynamic and kinetic factors of the process. We propose here a new approach to alloy
synthesis which involves step by step addition of constituent elements. In the present work, this is
illustrated through formation of nanocrystalline AlCoCrFeNi by mechanical alloying. For example,
first, binary CoNi is formed by milling elemental Co and Ni powders. In the subsequent steps, Fe,
Cr and Al are added to form ternary (CoNiFe), quaternary (CoNiFeCr) and then quinary
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(CoNiFeCrAl) alloy, respectively. Equiatomic compositions are ensured at each stage of the
sequence.
For a detailed investigation, three different classes of binaries have been selected as initial phases,
namely, B2 (AlNi, AlCo and AlFe), BCC (FeCr) and FCC (CoNi and FeNi). Remaining constituent
elements are added step-wise in varying sequences and equiatomic AlCoCrFeNi is obtained in the
final step. With such sequential additions, it is possible to enforce additional thermodynamic and
kinetic constraints that may stabilize a desired phase in the final multicomponent alloy. Phase
evolution at every stage of alloying is studied by X-ray diffraction. The final AlCoCrFeNi alloy at
the end of each sequence is not same but has varied fractions of BCC and FCC phases. For
example, AlCoCrFeNi obtained at the end of AlNi+Co+Fe+Cr sequence is single phase BCC,
whereas the sequence FeNi+Co+Cr+Al results in a mixture of BCC (77%) and FCC (23%) phases.
The extent to which a particular element stabilizes a structure (BCC/B2 /FCC) has also been
elucidated.
Keywords: High entropy alloys, Sequential addition, Mechanical Alloying
Sol-gel synthesis of yttrium monosilicate
1
Raghunandan Subbarao1, M. Kamaraj1and Ashutosh S. Gandhi2
Department of Metallurgical and Materials Engineering, IIT Madras, Chennai, India
2
Department of Metallurgical Engineering and Materials Science,
IIT Bombay, Mumbai, India
E-mail: [email protected]
Silicon-based ceramics are leading candidates to replace metallic components in the next generation
gas turbines. Silicon based ceramics show good oxidation resistance by forming a protective silica
layer on the surface. However, this layer is susceptible to water vapour attack in combustion
environments leading to recession of the silica layer. To prevent this recession, Si based ceramics
are coated with suitable materials. Rare earth silicates are potential environmental barrier coating
materials for Si based ceramics. Rare-earth silicates have higher temperature capability, lower
volatility and superior chemical compatibility compared to earlier EBC materials.
Sol-gel method is a promising technique to synthesize high-purity materials. In this work, yttrium
monosilicate is synthesized through sol-gel technique with yttrium nitrate and tetra ethyl
orthosilicate as the precursors by varying the pH of the sol. Various heat treatments were carried
out up to 1400°C to study the evolution of different phases. Obtaining phase pure yttrium
monosilicate has been challenging as impurity phases like yttrium disilicate, apatite and yttria
appear during the crystallization of the calcined gel. It is seen that highly acidic condition
minimizes the amount of impurity phases but does not prevent their formation. Thermodynamics of
phase selection during crystallization explains multiple phase formation. Annealing at 1400°C leads
to almost single-phase yttrium monosilicate. Also, the role of water in inducing the impurity phases
is evaluated.
Keywords: Environmental Barrier Coatings (EBCs), Yttrium Monosilicate, Sol-gel technique, Acid
Catalysis
69
Effect of deformation temperature on tensile and fracture properties of
Al 2014 alloy processed through multidirectional forging
Amit Joshi1, K. K. Yogesha1, Nikhil Kumar1 and R. Jayaganthan1,2
1
Department of Metallurgical and Materials Engineering & Centre of Nanotechnology,
Indian Institute of Technology Roorkee, Roorkee-247667, India
2
Department of Engineering Design,
Indian Institute of Technology Madras, Chennai-600036, India
E-mail: [email protected]
Effect of deformation temperature on tensile and fracture properties of Al 2014 Alloy subjected to
Multidirectional Forging (MDF) to a cumulative true strain of 1.2, 1.8, and 2.4 were investigated in
the present work. Al 2014 alloy were MDFed up to cumulative true strain of 1.2 (2 cycles), 1.8 (3
cycles), and 2.4 (4 cycles) at room and cryogenic temperature. The variation in mechanical
properties viz tensile strength, fracture toughness, and hardness due to the effect of Multidirectional
Forging was evaluated by UTM and Vickers hardness Tester. Microstructural changes due to the
effect of Multidirectional forging was investigated by optical and TEM while fracture surface
appearance after tensile and fracture toughness testing was observed by SEM. The MDFed samples
at cryogenic temperature up to a cumulative true strain of 2.4 shows an improvement of tensile
strength, hardness and apparent fracture toughness (KQ) from 318 MPa to 470 MPa, 103HV to 171
HV, and 23.93 MPa  to 37.7 MPa  respectively with decrease in ductility from 18% to 6% as
compared with solution treated alloy. Samples deformed at room temperature exhibited lower
strength, hardness, and ductility as compared to sample deformed at liquid nitrogen temperature.
Improvement of tensile properties of MDFed samples at cryogenic temperature as compared to
samples deformed at room temperature is attributed to the high dislocation density and suppression
of dislocation cross slip and climb associated at cryogenic temperature as observed from TEM
analysis. Fracture surface after tensile testing of MDFed samples up to a cumulative true strain of
2.4 at cryogenic temperature consists of bimodal dimpled features substantiating the increased
ductility of cryoforged Al 2014 alloy over the room temperature forged alloy as observed form
SEM while fracture mode in tensile testing of cryoforged alloy is transformed to the mixed mode
fracture from ductile fracture as compared to solution treated alloy.
Keywords: Multidirectional Forging, Tensile Strength, Fracture Toughness
Effect of annealing on the improvement of mechanical properties of low stacking
fault energy Cu-Al alloys processed by cryorolling
S. M. Dasharath and Suhrit Mula
Department of Metallurgical and Materials Engineering,
Indian Institute of Technology, Roorkee 247667, Uttarakhand, India
E-mail: [email protected]
Cu-2% Al and Cu-4.5% Al alloys were developed by metal mould casting and then annealed at
800°C for 4 h for homogenization of microstructure. The annealed samples were cryorolled up to
the maximum possible reduction in area (75% RA). After deformation at cryogenic temperature, a
remarkable 9-10 times improvement of yield strength (YS) was observed for both the alloys
compared to that of the homogenized samples. The recrystallisation temperature and activation
energy for the recrystallisation of the cryorolled samples were estimated through differential
scanning calorimetry at different heating rates. Annealing at 225°C for 20 min, the YS found to be
further improved (~5%) compared to that of the cryorolled samples. The cryorolling followed by
70
annealing at 250-300°C for the same duration showed an enhanced ductility with slight decrease in
the YS. Fractography analysis also authenticated with the tensile ductility and recrystallisation
behavior. The role of solid solution strengthening to the YS was estimated through the Labusch and
Voringer model. The contributions of other strengthening mechanisms were also analyzed to
corroborate the improvement of the mechanical properties, and the grain size strengthening found to
be the key mechanism for the enhanced YS. The solid solution strengthening by Al in Cu reduces
the stacking fault energy of Cu from 78 to 7 mJ/m2. At cryogenic temperature, it can be very
effective to prevent dynamic recovery and recrystallization; thus restricts cross slip to occur and
movement of dislocations. Thereby, it helps to increase twining activity for further deformation and
develop dislocation substructures/subgrains at the maximum deformation. Formation of subgrains
as well as nanotwins (confirmed by TEM study) has been found to play pivotal role in the
simultaneous improvement of strength and ductility.
Keywords: Cu-Al alloys; Cryorolling; nanotwins; Dislocation substructure; Stacking fault energy;
Electron microscopy.
Electrophoretic coating of nanostructured hydroxyapatite on Mg-3Zn alloy for
orthopedic application
Manoj Kumar R1, Kishor Kumar Kuntal2, Sanjay Singh1, Pallavi Gupta2, Bharat Bhushan2,
P.Gopinath2 and Debrupa Lahiri1
1
Department of Metallurgical and Materials Engineering, IIT Roorkee, India 247667
2
Centre for Nanotechnology, IIT Roorkee, India 247667
E-mail: [email protected]
In current research, magnesium alloys have gained a lot of attention as orthopaedic implant
material, due to its biodegradability and mechanical properties nearer to that of human bone.
However, one key drawback with use of Mg and its alloys as orthopaedic implants is their high
corrosion rate, which leads to fast deterioration and mechanical integrity of the implant before
proper healing of the bone tissue. In the present work, Mg alloy (Mg-3Zn) was coated with
nanostructured hydroxyapatite (HA) through electrophoretic deposition (EPD) technique. The
mechanical integrity of the coating and corrosion improvement is established as a function of
surface roughness of the substrate and annealing temperature of the coating. Lower substrate
roughness and higher annealing temperature of the coating shows uniform layer of hydroxyapatite
and better integrity with substrate. Mechanical properties such as fracture toughness and adhesion
strength of the surfaces helps in optimizing the coating conditions to get the better integrated HA
coating on Mg surface. Other hand, the HA coated surface shows a better corrosion resistance of the
Mg alloy surface during in vitro exposure. Bone cells are also found proliferating better in the HAcoated surface. All these results establish the potential of electrophoretic deposition of HA coating
on Mg-3Zn alloy in orthopaedic application.
Keywords: Hydroxyapatite, Electrophoretic deposition, Mechanical and corrosion property, Cell
Culture and biocompatibility behavior
71
Effect of grain refinement on mechanical behavior of Mg-2Gd-2Zn processed
through multiaxial forging and rolling
Raviraj Verma1, R. Jayaganthan2, S. K. Nath1and A. Srinivasan3
1
Department of Metallurgical and Materials Engineering,
IIT Roorkee, Roorkee - 247667, India
2
Department of Engineering Design, IIT Madras, Chennai - 600036, India
3
Materials Division, NIIST, Thiruvananthapuram - 695019, India
E-mail: [email protected]
The effect of grain refinement on tensile and fracture behavior of Mg-2Gd-2Zn alloy has been
investigated in the present work. The Mg-2Gd-2Zn alloy was subjected to multiaxial forging up to 2
cycles followed by rolling up to 75% reduction at 723K. The alloy was imparted solution treatment
at 723K for 5 hours prior to severe plastic deformation. The deformed samples were investigated for
tensile and fracture behavior and correlated with their microstructural features characterized
through Optical, SEM/EBSD, and TEM. The deformed samples showed increased tensile and
fracture resistance as compared to solution treated alloy due to grain refinement, find precipitates,
and higher dislocation density. The fracture morphology of the deformed samples has been altered
due to severe fragmentation of grains during SPD processing of the alloy. The tensile and fracture
behavior of the alloy are elucidated through SEM & TEM micrographs.
Keywords: Mg-2Gd-2Zn; Multiaxial forging; Rolling.
Predicting the stability of an HEA: a first-principles analysis
Meha Bhogra1, Umesh V. Waghmare1 and S. Ranganathan2
1
Theoretical Sciences Unit, JNCASR, Bangalore
2
Department of Materials Engineering, Indian Institute of Science, Bangalore-560064
E-mail: [email protected]
In the quest for engineering new materials with superior strength and ductility, there has been an
upsurge in the design and synthesis of multi-component alloys (also known as high-entropy alloys)
consisting of 4-5 elements in almost equi-atomic proportions. These alloy systems have shown
significant solid-solution strengthening and excellent high-temperature properties, and have been
found to exist primarily as a single phase, either in FCC or BCC structure. With the formation of a
medley of innumerable configurations at the atomic scale, the complex interactions among the coexisting elements, the stability of HEA in such simple structural forms (FCC or BCC) is still
enigmatic. Here, we use a combination of first-principles analysis, cluster expansion method and
machine learning algorithms to understand the origin of the structural stability of a solid solution of
5 elements in a particular structure at the atomic scale, in terms of the relative energies of vast
number of configurations. The energy of a configuration is then disintegrated into its elementary
clusters, the number densities of which are treated as the descriptors in a neural network. This
network obtains the relative contribution (weights) of each cluster in local stabilization or destabilization of an HEA.
72
Nanoscale quantitative magnetic information by EMCD and HREELS
D.S. Negi, B. Louky and R. Datta
International Center for Materials Science,
Jawaharlal Nehru Center for Advanced Scientific Research
Jakkur P.O., Bangalore-560064, India
E-mail: [email protected]
We describe quantitative evaluation of magnetic information at nanoscale by two different
techniques based on electron energy loss spectroscopy (EELS), namely, electron magnetic chiral
dichroism (EMCD) and high resolution electron energy loss spectroscopy (HR-EELS). While
EMCD yields information on atom specific individual spin and orbital moments, HR-EELS only
provide information on the relative magnetic order. The application of EMCD required
understanding the low signal and imbalance in signal between L3 and L2 absorption edges and
development of simple model for thickness dependent evaluation of magnetic moments for inverse
spinel magnetic crystals. With this development, EMCD was successfully applied for NiFe2O4 and
CoFe2O4 inverse spinel epitaxial thin films from regular structures, various levels of cation
inversions and a site cation defect areas. On the other hand the second technique HR-EELS has
been successful with the development of a soft technique to determine relative magnetic order
between the core and edge of CuCr2S4 nanocrystals. The beam damage during measurement,
difference between the two techniques and addressing various other magnetic phenomena with
these techniques at nanoscale will be highlighted.
Novel refractory high-entropy alloys
MoxNbTiVxZr(x = 0.3, 0.5, 0.75, and 1.0)
Ko-Kai Tseng and Jien-Wei Yeh
Department of Materials Science and Engineering,
National Tsing Hua University
E-mail: [email protected]
In this study, a new refractory high-entropy alloy series is developed with the compositions
MoxNbTiVxZr (x = 0.3, 0.5, 0.75, and 1.0). Their melting points are around 2000 C and densities
are around 7 g/cm3. Simple BCC structure is observed in the as-cast state. The formation of simple
solid solution phase mainly results from the high entropy effect and low bonding energies among
constituent elements. These alloys have Vickers hardness around 350 to 450 Hv and compressive
yield strength around 1000 to 1400 MPa. Impressively, Mo0.3NbTiV0.3Zr and Mo0.5NbTiV0.5Zr
possess the compressive ductility larger than 50%. Mo0.5NbTiV0.5Zr shows high thermal-softening
resistance and still has 850 MPa at 800 C . Comparing with single BCC HfNbTaTiZr alloy which
also has high compressive ductility (>50%), Mo0.5NbTiV0.5Zr has much higher yield strength and
specific yield strength.
Keywords: high-entropy alloys, refractory high-entropy alloys, high entropy effect
73
Microstructural evolution of In-situ Al-Mg2Si composites
Prosanta Biswas, Manas Kumar Mondal and Durbadal Mandal
Department of Metallurgical and Materials Engineering,
National Institute of Technology, Durgapur-713209, India
E-mail: [email protected]
Aluminium metal matrix composites (Al-MMCs) with In-situ Mg2Si particles reinforcement have a
great research interest due to their superior properties likelow density (1.88×103 kg m3), high
hardness (4.5×109Nm2), low thermal expansion coefficient(7.5×10-6 k1), a reasonably high elastic
modulus(120 GPa) and low cost.
In order to development of in-situ Al-Mg2Si composite, commercially pure Al (98%), Si (97%)
were melted with clay graphite crucible in an electrical resistance furnace at 760 °C and Mg was
added before poured into a standard cast iron mould. Microstructure evolution of these composites
was investigated with detailed phase identification and quantification by optical metallography, Xray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray
spectroscopy (EDS). Standard hardness was carried out to ascertain the hardness property.
The microstructure of developed in-situ Al-Mg2Si composites consist of primary Mg2Si phase
which is engulfed by α-Al phase and Al-Mg2Si binary eutectic phase. Besides, different phases are
identified using X-ray and EDS based SEM analysis. According to the Al-Mg2Siphase diagram,
Mg2Si particles are formed both as primary Mg2Si particles and secondary eutectic phases during
solidification. It also observed that -Al and secondary Mg2Sico-solidify from the liquid alloy in
the narrow ternary phase area. The size and shape of primary Mg2Si particles is varying with
addition of different wt.% of Mg and Si in Aluminium. In addition, it has increased the primary
Mg2Si particle size and its morphology is also changed from cubic to hopper like shape. The
hardness (40 VHN to 110 VHN) of the composite is increased with increase in volume fraction of
primary Mg2Si particles. Furthermore, the average sizes of primary Mg2Si particles are 10 µm, 36.5
µm and 53.5 µm respectively for Al-x wt.% Mg2Si (x = 10, 15, 20) composites.
Phase field study of static recrystallization and phase transformation during
intercritical annealing of dual phase steels
Ayush Suhane, Akash Bhattacharjee and Gerald Tennyson
Tata Research Development and Design Centre, Pune- 411028
E-mail: [email protected]
The properties of any material depend on the underlying microstructure. Spatial and temporal
evolution of microstructure is linked with processing parameters, which can be exploited further to
manufacture microstructural features for specific properties. Intercritical annealing is one such
crucial step in determining the macroscopic mechanical properties during thermomechanical
processing of cold rolled dual phase steels. Internal stored strain, heating rate and temperature-time
schedule play a major role in the kinetics of recovery, recrystallization and phase transformation,
thereby influencing the final microstructure. Final morphology and grain sizes are highly sensitive
to heating rates and holding temperature-time profiles during annealing. A phase field model is
developed to incorporate static recrystallization as a consequence of stored strain energy and ferrite
to austenite phase transformation due to chemical energy as a consequence of temperature. Initial
pancaked structure after cold rolling is constructed using voronoi tessellation. In order to track large
number of active phase fields, active parameter tracking algorithm was incorporated, thereby
74
simulating large and realistic systems. Grand Potential Formulation by Abhik and coworkers is
incorporated in Ginzburg-Landau time dependent equation to model phase transformation. The
study was done for different heating rates for a similar initial microstructure was performed. For a
particular region of heating rates, strong coupling between recrystallization and phase
transformation was observed. Morphology and grain size distribution were found to be highly
correlated with heating rates and thus with average mechanical property of the system.
Keywords: Microstructural evolution, static recrystallization, phase field, heat treatment, dual
phase steel
Mathematical modelling of grain growth during reheating
Himanshu Nirgudkar, Saurabh Mangal, Savya Sachi and Gerald Tennyson
TCS Research, Tata Research Development and Design Center, Pune
E-mail: [email protected]
Steel billets and slabs manufactured by the continuous casting route are generally hot rolled to
produce sheets of the required thickness. Prior to hot rolling, the steel stock is passed through a
reheating furnace to raise and homogenise the temperature across the cast slab. During reheating,
various microstructural changes occur. Composition homogenization in the dendritic arms,
dissolution of precipitates formed during casting, phase transformation and austenite grain
coarsening occur during reheating. It also improves the plastic deformation behaviour during hot
rolling. All these phenomena greatly influence the properties of the material during subsequent
operations which makes control of reheating operation critical.
A mathematical model is developed to obtain the temperature distribution in the slab when it passes
through the reheating furnace. Thermal radiation from the furnace walls and combustion gases
contribute towards the rise in temperature of the slab. The furnace is modelled as participating
medium and the net radiative heat flux is determined by solving the Radiative Transfer Equation.
This radiative heat flux is used as a boundary condition for solving the heat conduction equation in
the slab to obtain the temperature distribution in the slab. The temperature evolution across the slab
is used to model the growth of austenite phase as well as the dissolution of precipitate phase. One
dimensional diffusion simulations are performed using DICTRA which employs CALPHAD
thermodynamic and mobility databases. Austenite grain growth has been modelled based on
proposed constitutive equations and the effect of precipitate pinning the grain boundaries has also
been incorporated.
Keywords: Reheating furnace, thermal model, radiation, grain growth
Multiscale modelling of deformation behavior of DP steel
to obtain forming limit curve
Srimannarayana Pusuluri, Danish Khan and Arshdeep Singh,
Pramod Zagadeand B. P. Gautham
TCS Research, Tata Research Development and Design Centre, Pune
E-mail: [email protected]
In automotive industry, there is an increasing demand for materials which exhibit both high strength
and formability. Dual Phase (DP) steels, a class of advanced high strength steels (AHSS) owing to
75
the presence of ferrite and martensite phases in its microstructure exhibit these properties.
Prediction of mechanical properties of DP steel is a challenging task as it depends upon the
properties of constituent phases, their phase fractions, morphology and distribution of phases within
the microstructure andinter-phase interface properties. An attempt is made to address this issue by
performing a micromechanical Finite Element Analysis (FEA) on a Representative Volume
Element (RVE), which represents the microstructure of given DP steel,by incorporating appropriate
material models for constitutive phases and their interfaces. To simulate equivalent of macroscopic
deformation,periodic boundary conditions are applied to the RVE. Flow curves of constituent
phases, ferrite-martensite interface properties are input to the FE model. Flow curves of constituent
phases were assumed to obey phenomenological laws dependent upon the evolution of dislocation
density with plastic strain. Gurson-Tvergaard-Needleman (GTN) continuum damage model was
used to incorporate ductile damage in ferrite phase, whereas a simple Von-Mises yield function was
used for martensite phase as the deformation induced in it would be small before failure of RVE
occurs. Cohesive Zone Model (CZM) was used to describe the ferrite-martensite interface failure
behavior. To predict the forming limit curve for the given DP steel microstructure a multiscale
approach was adopted to reduce the computational cost. An initial uniaxial flow curve for the given
DP steel is obtained by performing FEA simulation on the RVE. This homogenized flow curve was
used in the macroscopic simulation of Marciniak-Kuczynski (M-K) analysis to obtain the forming
limit curve. ABAQUS has been used for performing the FEA, material models are implemented in
ABAQUS through its subroutine feature UMAT (User Defined Material).The obtained Uniaxial
Flow curve and Forming Limit Curve match quantitatively well with the published experimental
data.
Keywords: DP Steel, GTN, CZM, Uniaxial Flow Curve, Forming Limit Curve
Indentation response of microcrystalline and nanocrystalline
Ti-Ni-Cr-Co-Fe high entropy alloy
Abhijit1, G. M. Reddy2 and Koteswararao V. Rajulapati1
1
School of Engineering Sciences and Technology,
University of Hyderabad, Hyderabad 500046, India
2
Defence Metallurgical Research Laboratory, Hyderabad 500058, India
E-mail: [email protected]
High Entropy Alloys (HEAs) are alloys having at least five principal elements and all the principle
elements are mixed in equiatomic ratios. HEAs usually form only simple solid solutions with fcc
and/or bcc structures with no intermetallic compounds and hence have emerged as a new type of
advanced metallic materials. HEAs possess some excellent mechanical properties and have great
potential to be used as high temperature materials, coating materials requiring high hardness and
high wear resistance and corrosion resistance materials with high strength. In the current
investigation it is proposed to evaluate and compare the deformation characteristics of a
microcrystalline and nanocrystalline TiNiCrCoFe high entropy alloy. Multicomponent TiNiCrCoFe
high entropy alloy has been synthesized using vacuum arc melting. The alloy thus synthesizedwas
subjected to ball millingfor 30 hours at room temperature to refine the microstructuctural features.
Subsequently these powders were compacted using spark plasma sintering at temperatures of
0.5TM and 0.6TM(TM=theoretical melting point of this alloy). Structural/microstructural
characterization was done, at various stages, using optical microscopy, scanning electron
microscopy, transmission electron microscopy, x-ray diffraction etc. Mechanical properties were
evaluated on the compacted discs using microindentation and nanoindentation. In this paper,
structure-property correlations will be discussed.
Keywords: Nanocrystalline, High entropy alloys, indentation, mechanical properties
76
Strain hardening and flow properties of Nimonic C-263 alloy at different strain
rates and temperatures
Jhansi Jadav1,2, Koteswara Rao V. Rajulapati1,
N. Eswaraprasad3 and K. Bhanu Sankara Rao4
1
School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad
2
Department of Metallurgical and Materials Engineering,
Mahatma Gandhi Institute of Technology (MGIT), Hyderabad
3
Defence Materials & Stores R&D Establishment (DMSRDE), DRDO, Kanpur
4
Ministry of steel chair professor, MGIT, Hyderabad.
E-mail: [email protected]
The tensile testing of Nimonic C-263 alloy is done at a temperature range of 25-6500C and at
different strain rates (10-2 -10-4 S-1). The flow behaviour of Nimonic 263 alloy in peak aged
condition (ST/WQ/8000C/8h) at a strain rate of 10-3 S-1are analysed using different flow
relationships. Ludwigson relation provides the best fit for most of the experimental data for all
conditions. The strain hardening behaviour, at different temperatures is discussed. The presence of
Dynamic strain aging (DSA) behaviour is observed at a wide temperature regime of (25-6500C) and
(10-2 -10-4 S-1). Hence an anomalous variation in tensile properties is observed in the temperature
ranges between 4000C to 6000C. The yield strength is decreased slightly with temperature up to
3000C and then there is an increase in YS at 4000C and (%) of elongation is maximum at 5000C at a
strain rate of 10-3S-1. Characteristics of serrated flow behaviour is studied also SEM studies are
performed to understand the fracture behaviour at different strain rates and temperatures.
Influence of parent metal microstructure on the creep behaviour of Ti6Al4V
friction welds
Rahul1, K. V. Rajulapati1, G. M. Reddy2, T. Mohandas3 and K. Bhanu Sankara Rao4
1
School of Engineering Sciences and Technology,
University of Hyderabad, Hyderabad, 500046, India
2
Defence Metallurgical Research Laboratory, Hyderabad, 500058, India
3
Nalla Malla Reddy Engineering College, Hyderabad, 500088, India
4
Ministy of Steel (Govt. of India) Chair Professor,
Mahatma Gandhi Institute of Technology, Hyderabad-500075 India
E-mail: [email protected]
Gas Tungsten Arc Welding (GTAW) is widely employed during the fabrication of sheet metal
structures whereas discs are welded by electron beam welding. Excessive amounts of gases such as
oxygen, nitrogen etc. in titanium alloy causes embrittlement. In addition to this, fusion welds are
prone to solidification related defects such as weld porosity as well as other problems such as cold
cracking and loss of mechanical properties. Porosity results in scattered fatigue properties. In
orderto overcome these problems posed byfusion welding processes, attempts are being made to
introduce solid state joining processes like friction welding.The base metal microstructure has been
reported to have a significant influence on the fusion zone grain size of the alloy. The mechanical
properties and fracture characteristics would differ in the α+β and β conditions.
In the current investigation, the α+β titanium alloy has been successfully joined using rotary friction
welding.To investigate the influence of parent metal microstructure on the welds, the base metal
was heat treated inα+β and β conditions prior to friction welding.The creep behaviour of friction
welds wasstudied in the as-welded and the stress relieved conditions to understand the effect of
77
stress relieving on the microstructure and mechanical properties of the welds.Creep tests were
performed at 400oC and 320 MPa. Joints produced exhibited better creep resistance when compared
to the respective parent metal.
Keywords: Friction welding, Ti-alloys, Creep deformation, Microstructure
Superplastic behaviour of a new variant of AA 5456 alloy
J. Varghese1, K. A. Padmanabhan1,2, K. S. Suresh1 and D.V.V. Satyanarayana3
School of Engineering Sciences and Technology, University of Hyderabad, 500046, India
2
Centre for Nanotechnology, University of Hyderabad, 500046, India
3
Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh,
Hyderabad, 500058 India
1
E-mail: [email protected]
Superplastic Al-Mg alloys have attractive surface transport applications. A study characterizing the
superplastic behavior and the post deformation microstructure of a new variant (increased Mg, Cr
and decreased Fe content) of the AA5456 aluminium alloy was undertaken. The as-received alloy
was heat treated at different temperatures in the range 4500C to 575°C and for different
durationsbetween15 and 60 minutes in order to study the static grain growth behaviour. The study
revealed that soaking time did not have a significant effect on static grain growth. From strain rate
jump tests at different temperatures, strain rate sensitivity index (m) values in the range of 0.46 to
0.67 were obtained at 5500C.A maximum elongation of 440% was obtained when tested at the
condition which displayed the maximum m value.
Post deformation microstructural examination revealed that the shape of the grains following
extensive deformation remained essentially equiaxed indicating that deformation of the specimens
is predominantly by grain boundary sliding.The static grain growth in the grip section of the
sample, just due to long term thermal exposure is smaller than the dynamic grain growth present in
the guage section. This could be attributed to boththermal andstress-induced grain boundary
migration , the latter arising from deformation-induced plastic deformation accompanying grain
boundary sliding. Microstructural examination also revealed the presence of grain boundary
cavities, close to the fracture end of the tested specimens.The percentage area occupied by cavities
increases with test temperature and/or the extent of tensile deformation. The variation of width and
thickness (of the fractured samples) with distance from the fracture end was found to be more
uniform as the test temperature was increased. Experiments are in progress to understand grain
growth behavior and the role of dislocations in this grain growth process.
Keywords: AA5456, superplasticity, uniaxial tensile testing, deformation
An atomic cluster model to understand localized deformation behavior in
metallic glass
K.S.N. Satish Idury1, B. S. Murty2 and Jatin Bhatt1
1
Department of Metallurgical and Materials Engineering, V.N.I.T, Nagpur- 440 010
2
Department of Metallurgical and Materials Engineering, I.I.T Madras, Chennai- 600 036
E-mail: [email protected]
Metallic glasses (MGs) are promising class of materials with enhanced mechanical properties in
comparison to crystalline counterpart. MGs deform at room temperature through shear bands,
whose nucleation, propagation and interaction mechanisms are yet to be resolved. Though
78
indentation hardness is one of the principal parameter for depicting local deformation characteristics
of MG, its atomic portrayal remains far from being completely understood due to spatiotemporal
fluctuations of atomic short range order (SRO) during deformation experiments. Hence there exists
a need to clarify metallic glass deformation through atomic cluster perspective that will
subsequently pave way for understanding shear banding phenomenon. In this paper, we attempt to
model the deformation behavior using micro hardness at room temperature in Zr67Cu33 and
Zr42Cu50Ag8 glassy alloy ribbons at different loads. The indented morphologies and chemical
heterogeneity have been studied through scanning electron microscopy and EDAX analysis to
determine stress induced local chemistry change during deformation. The indented hardness
response of the ribbons is modeled by extending the cluster approach to systems mentioned. We
propose that the stochastic distribution in hardness value of bulk material can be closely related to
the modeled clusters. These clusters with different chemical stoichiometries are responsible for
dynamic reorganization of structural units to form shear band. Furthermore the origin of nucleation
and propagation of radial and circular shear bands in indented samples is discussed through cluster
dynamics viewpoint.
Keywords: Metallic glass, hardness, micro indentation, clusters dynamics.
Effect of varying soaking period during cryogenic treatment of
cubic boron nitride (CBN) cutting inserts
Swamini Chopra1, S. A. Pande2, K. N. Pande1, D. R. Peshwe1 and V. G. Sargade3
1
Dept. of Metallurgical and Materials Engineering, V.N.I.T. Nagpur, India
2
Dept. of Physics, Laxminarayan Institute of Technology, Nagpur, India
3
Dept. of Mechanical Engineering, Dr. B.A.T.U., Lonere, Maharahstra, India
E-mail: [email protected]
In this study, the effect of cryogenic treatment on the microstructural, chemical and mechanical
properties of CBN cutting insert was investigated. The inserts were cryo-treated at -185ºC in
cryostat for soaking period of 8, 16 and 24 hours. SEM and EDS indicated that the microstructure
and chemical composition of the CBN inserts remained unchanged with varying soaking periods.
However, XRD analysis revealed reduction in the average crystal size after cryogenic treatment.
This indicated formation of favourable state of residual stresses in the insert. It was also observed
that the microhardness of CBN inserts increased after soaking of 8 and 16 hours. A study of surface
roughness and 3-D surface profile after cryogenic treatment was carried out to investigate the
surface asperities. Thus, the soaking period for the cryogenic treatment of CBN insert was
optimized.
Keywords: cryogenic treatment, soaking period, CBN inserts, tool life
79
International Conference on Metals and Materials Research (ICMR 2016)
June 20-22, 2016
Indian Institute of Science, Bangalore, India
List of Registered Delegates
S.N
o.
Name
Affiliation
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Abhijit
T. A. Abinandanan
Dilshad Akhtar
V. S. Arunachalam
C. N. Athreya
Sumit Bahl
Srinivasa Rao Bakshi
R. Balamuralikrishnan
N. Balasubramanian
Dipankar Banerjee
Rajarshi Banerjee
Srikumar Banerjee
Srimanta Barui
Bikramjit Basu
Joysurya Basu
Chris Berndt
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
T.A. Bhaskaran
Meha Bhogra
Prosanta Biswas
Barry Carter
Supriyo Chakraborty
Sanjivi
Chandrasekharan
Kaushik Chatterjee
K. Chattopadhyay
Swamini Chopra
Abhik Choudhary
Atasi Dan
Dasharath S M
Ranjan Datta
Pravin P. Deshpande
G. K. Dey
C. Dong
Univ. of Hyderabad
IISc, Bangalore
DRDO, Delhi
CSTEP, India
IIT Madras
IISc, Bangalore
IIT Madras
DMRL, Hyderabad
Bangalore
IISc, Bangalore
Univ. of North Texas, USA
BARC, Mumbai
IISc, Bangalore
IISc, Bangalore
IIT BHU, Varanasi
Swinburne Univ. of
Technology, Australia
NAL, Bangalore
JNCASR, Bangalore
NIT, Durgapur
Univ. of Connecticut, USA
IISc, Bangalore
TCS, Chennai
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
Pradip Dutta
Hamish Fraser
Yu Fuxiao
Chanchal Ghosh
Partha Ghoshal
E. S. Raja Gopal
S. Gopalkrishnan
Jagadeesh Gopalan
Poorwa Gore
Gouthama
A. L. Greer
IISc, Bangalore
IISc, Bangalore
VNIT, Nagpur
IISc, Bangalore
IISc, Bangalore
IIT Roorkee
JNCASR, Bangalore
COEP, Pune
BARC, Mumbai
Dalian Univ. of
Technology, China
IISc, Bangalore
Ohio State University, USA
North Eastern Univ., China
IGCAR, Kalpakkam
DMRL, Hyderabad
IISc, Bangalore
IISc, Bangalore
IISc, Bangalore
IIT Bombay
IIT Kanpur
Univ. of Cambridge, UK
80
E-mail Id
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
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[email protected]
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[email protected]
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NileshGurao
B. Gurumoorthy
M. Gururajan
Guruvidyathri K
K.S.N. Satish Idury
A. Inoue
Jhansi Jadav
Piyush Jagtap
J. Jayaraj
Vikram Jayaram
Amit Joshi
Satish V. Kailas
Vivekanand Kain
Samir V. Kamat
Sivaji Karna
S. Kashyap
Dr. Alim Khan
Anuj Khond
Maya K. Kini
IIT Kanpur
IISc, Bangalore
IIT Bombay
IIT Madras
VNIT, Nagpur
Tohoku University, Japan
Univ. of Hyderabad
IISc, Bangalore
IGCAR, Kalpakkam
IISc, Bangalore
IIT Roorkee
IISc, Bangalore
BARC, Mumbai
DMRL, Hyderabad
DMRL, Hyderabad
IISc, Bangalore
Ametek, Delhi
VNIT, Nagpur
IISc, Bangalore
63.
64.
65.
66.
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71.
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Ravi S Kottada
M. Ajay Krishnan
R. Krishnan
Abinash Kumar
Anurag Kumar
Nirmal Kumar
Manoj Kumar R
Dr. Parveen Kumar
Subodh Kumar
Subhajit Kundu
S. Lele
Shantanu Vijay Madge
Giridhar Madras
Bhaskar Majumdar
R.K. Mandal
Sourav Mandal
S. Manjini
I. Manna
Avanish Mishra
N.S. Mishra
Sanak Mishra
84.
85.
86.
87.
Sumeet Mishra
Shikhar Misra
Rahul Mitra
Vinci Mojamdar
IIT Madras
IIT Bombay
GTRE, Bangalore
MRC IISc, Bangalore
IISc, Bangalore
IIT Kanpur
IIT Roorkee
CSTEP, Bangalore
IISc, Bangalore
IISc, Bangalore
IIT BHU, Varanasi
NML, Jamshedpur
IISc , Bangalore
DMRL, Hyderabad
IIT BHU, Varanasi
IISc, Bangalore
JSW, Mumbai
IIT Kanpur
IISc, Bangalore
NIFFT, Ranchi
Indian Steel Association,
New Delhi
IIT Kanpur
IIT Kanpur
IIT Kharagpur
IISc, Bangalore
88.
89.
90.
91.
92.
93.
U. Kamachi Mudali
N. K. Mukhopadhyay
K. Muraleedharan
B. S. Murty
I. Nagabhusan
Kazuhiro Nagata
94.
C.G.K. Nair
IGCAR, Kalpakkam
IIT BHU, Varanasi
CGCRI, Kolkata
IIT Madras
Gatan, Mumbai
Tokyo Institute of
Technology, Japan
SIATI, Bangalore
81
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95.
96.
97.
98.
99.
100.
101.
102.
103.
104.
P. Ramesh Narayanan
Sharmistha Naskar
K.A. Natarajan
D. S. Negi
Himanshu Nirgudkar
S.N. Ojha
P. Padaikathan
Manish Patel
Chandra Shekhar
Perugu
M. Phaniraj
105.
106.
107.
108.
G. Phanikumar
Pradip
K.G. Pradeep
Om Prakash
109.
110.
M.J.N.V. Prasad
N. Eswara Prasad
111.
112.
113.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
130.
Rajesh Prasad
Rudra Pratap
Srimannarayana
Pusuluri
Raghunandanan S
Rahul
Baldev Raj
V.S. Raja
S. Raju
Praveen C.
Ramamurthy
S. Ranganathan
Rajeev Ranjan
C.N.R. Rao
P. Rama Rao
V.A. Ravi
C. Ravindran
John Rodgers
Satyam Sahay
M.S.M. Saifullah
R. Sankarasubramanian
S. Seetharaman
131.
132.
133.
134.
135.
136.
137.
138.
139.
140.
141.
142.
R. Anand Sekhar
M N Chandra Sekhar
Nagaraju Sesetty
Vijay Sethuraman
Yagnesh Shadangi
P. Shankar
Amit Sharma
Maya Sharma
S.C. Sharma
Vikas Shivam
Anoop Shukla
Aditya Narayan Singh
114.
115.
116.
117.
118.
119.
VSSC, Trivandrum
IISc, Bangalore
IISc, Bangalore
JNCASR, Bangalore
TRDDC, Pune
IIT BHU, Varanasi
IISc, Bangalore
DMRL Hyderabad
IISc, Bangalore
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Seoul National Univ.,
South Korea
IIT Madras
TCS, Pune
Germany
Boeing International Corp.,
Bangalore
IIT Bombay
DMSRDE, Kanpur
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
IIT Delhi
IISc, Bangalore
TRDDC, Pune
[email protected]
[email protected];
[email protected]
[email protected]
[email protected]
[email protected]
IIT Madras
Univ. of Hyderabad
NIAS, Bangalore
IIT Bombay
IGCAR, Kalpakkam
IISc, Bangalore
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
IISc, Bangalore
IISc, Bangalore
JNCASR, Bangalore
ARCI, Hyderabad
Cal Poly Pomona, USA
Ryerson University, Canada
Nanoholdings, USA
John Deere, Pune
Singapore
DMRL, Hyderabad
Royal Institute of
Technology, Sweden
IIT Madras
Bangalore
BARC, Mysore
IISc, Bangalore
IIT BHU, Varanasi
Saveetha Univ., Chennai
IISc, Bangalore
IISc, Bangalore
VSSC, Trivandrum
IIT BHU, Varanasi
VSSC, Trivandrum
IGCAR, Kalpakkam
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
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[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
143.
144.
145.
146.
147.
148.
149.
150.
NIMS, Japan
MRC IISc, Bangalore
GE, Bangalore
NIAS, Bangalore
IISc, Bangalore
BARC, Mumbai
BHU, Varanasi
North Texas, USA
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
IIT Madras
[email protected]
152.
153.
154.
155.
156.
Alok Singh
Nisha Singhania
Dheepa Srinivasan
Sharada Srinivasan
Chandan Srivastav
Dinesh Srivastava
O.N. Srivastava
Srinivasan G.
Srivilliputtur
Raghunandan
Subbarao
Anandh Subramaniam
G Subramanian
S. Subramanian
Ayush Suhane
Satyam Suwas
IIT Kanpur
IIM Bangalore
IISc, Bangalore
TRDDC, Pune
IISc, Bangalore
157.
158.
R. S. Tiwari
Ko-Kai Tseng
159.
160.
161.
162.
163.
164.
165.
166.
167.
A.M. Umarji
Mayur Vaidya
J. Varghese
Vijay Vasudevan
Raviraj Verma
N.N. Viswanathan
Umesh Waghmare
T.P. Yadav
J.W. Yeh
168.
Wenzheng Zhang
BHU, Varanasi
National Tsing Hua
University, Taiwan
IISc, Bangalore
IIT Madras
Univ. of Hyderabad
Univ. of Cincinnati, USA
IIT Roorkee
IIT Bombay
JNCASR, Bangalore
BHU, Varanasi
National Tsing Hua Univ.,
Taiwan
Tsinghua Univ., Beijing
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
n
[email protected]
[email protected]
151.
83
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
International Conference on Metals and Materials Research (ICMR 2016)
June 20-22, 2016
Indian Institute of Science, Bangalore, India
List of Sponsors
S.No.
Name of the Sponsor
Nature of the Sponsor
1.
Atomic Energy Regulatory Board (AERB)
Government sponsor
2.
Board of Research in Nuclear Sciences (BRNS)
Government sponsor
3.
Defence Research and Development Organization
(DRDO)
Government sponsor
4.
Indian Space Research Organisation (ISRO)
Government sponsor
5.
Department of Chemicals and Petrochemicals
Ministry of Chemicals and Fertilizers (MCF)
Steel Authority of India (SAIL)
Government sponsor
Government sponsor
8.
Science and Engg. Research Board (SERB)
Department of Science & Technology (DST)
Icon Analytical
9.
General Electrics (GE)
Platinum Sponsor
10.
JSW Steel Ltd. (JSW)
Platinum Sponsor
11.
Tata Steel
Platinum Sponsor
12.
Gatan
Gold Sponsor
13.
Ametek
Silver sponsor
14.
Center for Study of Science, Technology and Policy
(CSTEP)
Silver sponsor
15.
Hysitron
Silver sponsor
16.
TATA Consultancy Services (TCS)
Silver sponsor
17.
Central Glass Ceramic Research Institute(CGCRI)
Session sponsor
18.
National Metallurgical Laboratory (NML)
Session sponsor
19.
Nanoholdings
Session sponsor
20.
Panalytical
Session sponsor
21.
Anarghya Innovations and Technologies Pvt. Ltd.
Other sponsor
22.
TVS Motors
Other sponsor
6.
7.
84
Government sponsor
Banquet sponsor
85
86
87
88
89
90
91
92
93
ICMR-2016 Advisory Committee
T A Abinandanan, IISc, Bangalore, India
V S Arunachalam, CSTEP, India
M F Ashby, University of Cambridge, UK
Dipankar Banerjee, IISc, Bangalore, India
Srikumar Banerjee, DAE, Mumbai, India
David G Brandon, Israel Inst. of Technol., Israel
Barry Carter, University of Connecticut, USA
Kamanio Chattopadhyay, IISc, Bangalore, India
G K Dey, BARC, Mumbai, India
C Dong, Dalian University of Technol., China
Yu Fuxiao, North Eastern University, China
A L Greer, University of Cambridge, UK
A Inoue, Tohoku University, Japan
Vikram Jayaram, IISc, Bangalore, India
Samir V Kamat, DMRL, Hyderabad, India
Ramesh Kolar, ONR Global, Singapore
R Krishnan, GTRE, Bangalore, India
S Lele, IIT BHU, Varanasi, India
E A Lord, IISc, Bangalore, India
R K Mandal, IIT BHU, Varanasi, India
I Manna, IIT Kanpur, India
K Muraleedharan, CGCRI, Kolkata, India
K Nagata, Tokyo, Japan
Baldev Raj, NIAS, Bangalore, India
E G Ramachandran, IIT Madras, India
P Rama Rao, ARCI, Hyderabad, India
B B Rath, Naval Research Laboratory, USA
S Seetharaman, KTH, Sweden
S Srikanth, NML, Jamshedpur, India
G Sundararajan, ARCI, Hyderabad, India
B N Suresh, INAE, India
A Takeuchi, Tohoku University, Japan
M Vijayalakshmi, IGCAR, Kalpakkam, India
Umesh Waghmare, JNCASR, Bangalore, India
J W Yeh, National Tsing Hua Univ., Taiwan
ICMR-2016 Organising Committee
V S Raja, IIT Bombay, Chairman
N K Mukhopadhyay, IIT BHU, Co-Chairman
Satyam Suwas, IISc, Bangalore, Co-Chairman
B S Murty, IIT Madras, Convener
Vijay Sethuraman, IISc, Bangalore, Secretary
Abhik Choudhury, IISc, Bangalore, Treasurer
G Subramanian, IIM Bangalore Chapter
N Ravishankar, IISc, Bangalore
Bikramjit Basu, IISc, Bangalore
Chandan Srivastava, IISc, Bangalore
Materials
artners
Alliance P
Partners
Hysitron
Gatan
Gold Sponsor
General Electric
M
a
t
e
r
ia
ls
Alliance
Platinum Sponsors
JSW Steel Ltd.
Silver Sponsors
Centre for Study of Science,
Technology and Policy
Panalytical
Session Sponsors
Nanoholdings
Other Sponsors
TVS Motors
Central Glass Ceramic Research Institute, Kolkata
Anarghya Innovations and
Technologies Pvt. Ltd.
National Metallurgical
Laboratory, Jamshedpur
TATA Consultancy Services
Icon Analytical
Banquet Sponsor
TATA Steel
International Conference on Metals and Materials Research (ICMR 2016)
June 20 - 22, 2016 @ Indian Institute of Science, Bengaluru, India
Organised by
T R Anantharaman
Education and Research
Foundation
Electron Microscope Society of India
Department of Metallurgical Engg,
Indian Institute of Technology,
Banaras Hindu University
in Collaboration with
The Indian Institute of Metals, Bangalore Chapter
Metal Sciences Division, The Indian Institute of Metals
Department of Materials
Engineering, Indian Institute of
Science, Bangalore
Indian National Science Academy
Steel Authority of India
Science & Engg. Research Board
Dept of Science & Technology
Government of India
Board of Research
in Nuclear Sciences
Department of Chemicals and Petrochemicals
Ministry of Chemicals and Fertilizers
Government of India
Atomic Energy
Regulatory Board
Government Sponsors
National Institute of Advance Studies, Bangalore
Indian Space
Research Organisation
Defence Research and
Development Organization

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