here - Department of Engineering Science

Transcription

Detailed Programme and Abstract Proceedings
UK-Japan Symposium 2015 on Materials Under Extreme Conditions:
Effects of Temperature, High Strain Rate and Irradiation
20 – 23 September 2015, University of Oxford, United Kingdom
Organised by University of Oxford and Tokyo Institute of Technology
under the auspices of the UK-Japan Engineering Education League
http://www.eng.ox.ac.uk/solidmech/ukjapan2015
Last updated: 20th September 2015
UK-Japan Symposium on Materials Under Extreme Conditions:
Oxford, United Kingdom, 20-23 September 2015
Contents
Foreword .......................................................................................................................................... 2
Organising Committee and Editors .................................................................................................... 2
Map of Pembroke College ................................................................................................................. 4
Programme overview ........................................................................................................................ 5
Detailed programme ......................................................................................................................... 6
Topics for student groupwork presentation ..................................................................................... 10
Name list for the groupwork presentation ....................................................................................... 11
List of Abstracts and Abstracts ......................................................................................................... 12
1
Foreword
In many industrial sectors – for instance those dealing with power generation,
transportation, infrastructure and defence – advanced alloys are being pushed to the
very limits of their capability. Examples include ever higher operating temperatures and
pressures, high strain rates and harsh environments involving corrosion and nuclear
irradiation. These are materials required to work under extreme conditions.
What impact do these hostile environments have on the material’s operating lifetimes?
How do engineers design with them to meet industry’s needs but also to ensure the
safety demanded by society? What is the underlying material science that allows for
effective use of these advanced materials at extreme conditions?
To address these pressing issues, a UK-Japan Symposium on Materials Under Extreme
Conditions will bring together leading experts from around the world. Emphasis will be
placed on cutting-edge science and research, with plenty of time for discussion and
interaction including a groupwork project for students. The symposium is being
organised jointly by the University of Oxford* and Tokyo Institute of Technology, under
the auspices of the UK-Japan Engineering League†.
Organising Committee and Editors
University of Oxford
Tokyo Institute of Technology
Prof. Roger C. Reed
Prof. Kikuo Kishimoto
Dr. Fauzan Adziman
Prof. Jeffrey Cross
Mrs. Karen Bamford
Prof. Masao Takeyama
*
As the oldest university in the English-speaking world, University of Oxford is a unique and historic institution.
Teaching existed at Oxford in some form in 1096 and developed rapidly from 1167.
†
The UK-Japan Engineering Education League was founded at Tokyo Tech in March 2014, where it held its first
symposium. A second meeting took place at UCL in London in September 2014. The league consists of more than 20
Japanese and UK research universities which hold meetings to exchange information, to establish best practice in
engineering education and to promote education through research.
2
Keynote Lectures
Role of Metals in Society
Prof. Roger C. Reed
University of
Oxford
Novel Concept of Alloy Design for Power Generation
Tokyo Institute of
Technology
Nickel Superalloys for Jet Engine Applications
Prof. Cathie Rae
University of
Cambridge
High-temperature Oxidation of Metals
Prof. Shigenari Hayashi
Tokyo Institute of
Technology
Effects of Nuclear Irradiation of Structural Alloys
Prof. David Armstrong
University of
Oxford
Titanium Alloys at the Extreme
Prof. David Dye
Imperial College
London
Technical Lectures
Thermal Barrier Coatings
Dr. Rudder Wu
NIMS, Japan
Dynamic Failure of Materials and Structures
Prof. Kazuaki Inaba
Tokyo Institute of
Technology
Modelling Methods for Design of New Alloys
Dr. Alessandro Mottura
University of
Birmingham
Thermal Mechanical Fatigue
Prof. Johan Moverare
Linköping
University, Sweden
Spraying Technology for Coatings
Dr. Atsushi Sato
University of
Oxford
Role of Physics-based Modelling
Dr. Fauzan Adziman
University of
Oxford
Plasticity and Beyond in Nickel Superalloys
Prof. Motoki Sakaguchi
Tokyo Institute of
Technology
Materials at High Strain Rates
Dr. Antonio Pellegrino
University of
Oxford
Overview of 9Cr-1Mo Steel Oxidation Behaviour in
Advanced Gas Cooled Reactors
Dr. Aya Shin
EDF Energy, UK
3
Map of Pembroke College
4
With opening and introductory remarks by
Programme
overview
Sunday, 20th
September 2015
Breakfast*
starts at
08.00 for
lecture
starts at
09.00
Refer to
detailed
programme
below
Prof. Roger C. Reed
Prof. Kikuo Kishimoto
Tokyo Institute of Technology
Prof. Roderick Smith
Imperial College London
Minister (Economic)
Hiroshi Matsuura
Embassy of Japan in the
United Kingdom
Monday, 21st
September 2015
Tuesday, 22nd
September 2015
Wednesday, 23rd
September 2015
Keynote
lectures
(3 x 40 min)
Keynote
lectures
(3 x 40 min)
Group
presentations by
student
(3 groups)
Coffee break
Coffee break
Coffee break
Student
presentations
(4 x 20 min)
Student
presentations
(4 x 20 min)
Group
presentations by
student
(3 groups)
Lunch in Hall
Lunch in Hall
Lunch in Hall
Groupwork
project for
students
Technical
lectures
(4 x 20 min)
Registration
Networking and
discussion for
other delegates
19.00
*
Coffee break
Departures
Poster session
Coffee during
session
Technical
lectures
(4 x 20 min)
Welcome drinks
reception & dinner
Dinner
Formal dinner
Breakfast in Dining Hall is only for delegates who stay at Pembroke College Oxford.
5
Detailed programme
Sunday 20 September 2015
13.30
Registration
Preparation: for students to attach posters before 15.30 hrs
16.00
Student poster session and competition*
*Winners of the best 8 posters, which will be selected by all
delegates including a panel of judges, are entitled to do oral
presentation on 21st or 22nd September
Chairs: Dr Fauzan Adziman, Prof. Roger Reed, Prof. Kikuo Kishimoto
19.00
Welcome drinks reception and dinner
Introductory remarks by Prof. Roger Reed (Oxford University)
and Prof. Masao Takeyama (Tokyo Institute of Technology)
Harold Lee Room
Hall
Monday 21 September 2015
08.00
Breakfast*
Hall
Keynote lectures and student presentations
Chair: Prof. Roger Reed
09.00
Keynote: Role of Metals in Society
Prof. Roger Reed
University of Oxford, UK
09.40
Keynote: Novel Concept of Alloy Design for Power Generation
Tokyo Institute of Technology, Japan
10.20
Keynote: Titanium Alloys at the Extreme
Prof. David Dye
Imperial College London, UK
11.00
Coffee
11.30
The Improving Graphene Transfer by Changing Transfer
Variables
Harold Lee Room
Harold Lee Room
Yo Kan 1,2, Ella Carlsen-O'Conor 1, Adrian Murdock 1, Christian van
Engers 3, Nicole Grobert 1
1. Department of Materials, University of Oxford, UK
2. Tokyo Institute of Technology, Japan
3. Department of Chemistry, University of Oxford, UK
*
6
11.50
Surface Phase Transformation in Austenitic Stainless Steel
Induced by Cyclic Oxidation in Humidified Air
Mattias Calmunger 1, Robert Eriksson 2, Guocai Chai 1,3, Sten
Johansson 1, Johan J. Moverare 1
1. Department of Management and Engineering, Linköping
University, Sweden
2. Siemens AG, Berlin, Germany
3. AB Sandvik Materials Technology R&D Center, Sweden
12.10
Fabrication of Al-Cu/pure Al Clad Strips by Vertical-type
Tandem Twin-roll Casting
Tomomi Sugiyama, Yusuke Takayama, Yohei Harada, Shinji Kumai
Department of Metallurgy and Ceramics Science, Tokyo Institute of
Technology, Japan
12.30
A Study of Superplasticity in Ti-6Al-4V
Enrique Alabort, Roger C. Reed
Department of Engineering Science, University of Oxford, UK
12.50
Lunch
Hall
Groupwork projects for students
Chair: Prof. Jeffrey Cross
14.00
Groupwork project for students
Coffee will be served during session
Harold Lee Room
Networking and discussion for other delegates
14.00
Networking and discussion
Coffee will be served during session
Senior Common
Room Parlour
16.30
Walking tour of Oxford
by a professional guide
Depart from
Harold Lee Room
19.00
Dinner
Hall
Tuesday 22 September 2015
08.00
Breakfast*
Dining Hall
Keynote lectures and student presentations
Chair: Prof. Roger Reed
09.00
Keynote: Nickel Superalloys for Jet Engine Applications
Prof. Cathie Rae
University of Cambridge, UK
09.40
Keynote: High-Temperature Oxidation of Metals
Prof. Shigenari Hayashi
*
Harold Lee Room
7
10.20
Keynote: Effects of Nuclear Irradiation of Structural Alloys
Prof. David Armstrong
11.00
Coffee
11.30
Wave Propagation across Solid-Fluid Interface with FluidStructure Interaction
Tomohisa Kojima, Kazuaki Inaba, Kosuke Takahashi, Kikuo
Kishimoto
Department of Mechanical Sciences and Engineering, Tokyo
Institute of Technology, Japan
11.50
Oxidation Behavior of a Single Crystal Ni-based Superalloy at
Low Service Temperatures
Angelos Evangelou 1, Philippa Reed 1, Scott Lockyer 2, Katherine
Soady 2
1. Department of Engineering and the Environment, University of
Southampton, UK
2. E.ON Technologies (Ratcliffe) Limited, Nottingham, UK
12.10
Precipitation of GCP and TCP Phases at Grain Boundaries in
Wrought Ni- base Alloys
Shuntaro Ida , Satoru Kobayashi, Masao Takeyama
Department of Metallurgy and Ceramics Science, Tokyo Institute of
Technology, Japan
12.30
Ab Initio Study of the Effect of Solute Atoms on The Vacancy
Diffusion in Ni-based Superalloys
Kamal Nayan Goswami, Alessandro Mottura
School of Metallurgy and Materials, University of Birmingham, UK
12.50
Lunch
Harold Lee Room
Dining Hall
Technical lectures
Chair: Prof. Masao Takeyama
14.00
Technical Lecture: Thermal Mechanical Fatigue
Prof. Johan Moverare
Linköping University, Sweden
14.20
Technical Lecture: Dynamic Failure of Materials and
Structures
Prof. Kazuaki Inaba
14.40
Technical Lecture: Materials at High Strain Rates
Dr Antonio Pellegrino
15.00
Technical Lecture: Role of Physics-based Modelling
Dr Fauzan Adziman
15.20
Coffee
Harold Lee Room
8
Technical lectures
Chair: Prof. Cathie Rae
15.50
Technical Lecture: Plasticity and Beyond in Nickel
Superalloys
Prof. Motoki Sakaguchi
Harold Lee Room
16.10
Technical Lecture: Modelling Methods for Design of New
Alloys
Dr Alessandro Mottura
University of Birmingham, UK
16.30
Technical Lecture: Thermal Barrier Coatings
Dr Rudder Wu
National Institute of Materials Science, Japan
16.50
Technical Lecture: Spraying Technology for Coatings
Dr Atsushi Sato
17.10
Technical Lecture: Overview of 9Cr-1Mo Steel Oxidation
Behaviour in Advanced Gas Cooled Reactors
Dr Aya Shin
EDF Energy, UK
18.30
Drinks reception and group photo session
Garden in front
of Hall*
19.00
remarks
at 19.20
Formal dinner
Remarks by Prof Roderick Smith (Imperial College London),
Prof Kikuo Kishimoto (Tokyo Institute of Technology), and
Minister (Economic) Hiroshi Matsuura (Japan Embassy in the UK)
Hall
Wednesday 23 September 2015
08.00
Breakfast†
Hall
Group presentation by students
Chair: Prof. Jeffrey Cross
09.00
Group presentation by students – Group 1
09.30
10.00
10.30
Coffee
11.00
11.30
12.00
*
†
Harold Lee Room
Weather permitting, alternatively in Dining Hall.
9
12.30
Wrap Up session and closing
Profs Kikuo Kishimoto, Masao Takeyama and Roger Reed
13.00
Lunch
14.00
Departures
Hall
Addendum
After the symposium we will host UK - Japan Engineering Education League meeting
Contact persons:
Professors Jeffrey Cross and Kikuo Kishimoto (Tokyo Institute of Technology), Roderick
Smith (Imperial College London), Roger Reed and Steve Sheard (University of Oxford).
Time: Wednesday, 23 September 2015, 13.30 -15.00
Location: Senior Common Room (SCR) Parlour, Pembroke College Oxford.
Topics for student groupwork presentation
1.
2.
3.
4.
5.
6.
Ph.D. Program Training: Comparison and analysis between Japan and UK/Europe Universities
Energy Policy in UK/Europe and Japan: Similarities and Differences
Science or Engineering: What Contributes More to Society?
The Public Perception of Science and Engineering in UK/Europe and Japan: How Do They Differ?
Possibilities for Recycling of Metals: Japan and UK/Europe
New Propulsion Strategies for Cars, Trains and Airplanes
10
Name list for the groupwork presentation*
No
First Name
Group 1
1
Tomohisa
2
Akira
3
Viktor
4
Paraskevas
5
Ana
Group 2
6
Yuri
7
Hiromu
8
Mattias
9
Andre
10 Abigail
Group 3
11 Yo
12 Hidekazu
13 Sohya
14 Lluís
15 Enrique
Group 4
16 Inci
17 Yuji
18 Samuel
19 Angelos
20 Sabin
Group 5
21 Mari
22 Shuntaro
23 Kamal
24 Yilun
25 Paul
Group 6
26 Daniel
27 Tomomi
28 Shunichi
29 Bentang Arief
30 Ted
31 Regina
Surname
Name of Institution
Kojima
Yamauchi
Norman
Kontis
Casanova
Iguchi
Hisazawa
Calmunger
Nemeth
Ackerman
Kan
Arai
Kudoh
Pérez Caro
Alabort
Luleå University of Technology, Sweden
Akcam
Takeda
Hammarberg
Evangelou
Muntean
Kyushu University, Japan
University of Southampton, UK
Yoshihara
Ida
Goswami
Gong
Mulvey
Birmingham University, UK
Barba
Sugiyama
Nakayama
Budiman
Sjöberg
Schlutter
Tohoku University, Japan
Chair: Professor Jeffrey Cross (Tokyo Institute of Technology)
Tutors: Dr Atsushi Sato (University of Oxford), Dr David Crudden (University of Oxford), Dr Aya Shin (EDF Energy,
UK – PhD from University of Cambridge), Dr Rudder Wu (NIMS – PhD from Imperial College London), Dr Kosuke
Takahashi (Tokyo Institute of Technology), Dr Fauzan Adziman (University of Oxford)
*
All 31 students are post-graduate students
11
List of Abstracts and Abstracts
12
List of Abstracts
(Following alphabetical order of first author’s surname)
Keynote Lectures
Effects of Irradiation on Structural Nuclear Alloys ................................................................................................... 15
David E.J Armstrong ............................................................................................................................................. 15
High-Temperature Oxidation of Metals ................................................................................................................... 16
Shigenari Hayashi ................................................................................................................................................. 16
Yield and Creep Mechanisms in Superalloys ............................................................................................................ 17
C.M.F Rae, O.M.M.D. Mésse, N. Tabrizi and Y. Wang-Koh .................................................................................. 17
Technical Lectures
Role of Physics-based Constitutive Modelling of Metals ......................................................................................... 18
Fauzan Adziman*, Nik Petrinic, Roger Reed ......................................................................................................... 18
Dynamic Failure of Materials and Structures ........................................................................................................... 19
Kazuaki Inaba*, Kosuke Takahashi, Kikuo Kishimoto ............................................................................................ 19
Modelling Methods for Design of New Alloys.......................................................................................................... 20
Alessandro Mottura ............................................................................................................................................. 20
Thermal Mechanical Fatigue .................................................................................................................................... 21
Johan Moverare ................................................................................................................................................... 21
Materials at High Strain Rate ................................................................................................................................... 22
Antonio Pellegrino*, Nik Petrinic ......................................................................................................................... 22
Effect of Plastic and Creep Strains on the Microstructural Changes in a Single Crystal Ni-base Superalloy ........... 23
Motoki Sakaguchi 1,*, Masakazu Okazaki 2 ........................................................................................................... 23
Manufacture of Ultra-low Segregation Billets to Enable Novel Ni Superalloy Compositions for Extreme Condition
Applications.............................................................................................................................................................. 24
Atsushi Sato1, Masaki Taneike2, Ikuo Okada2, Patrick S. Grant1,* ......................................................................... 24
Overview of 9Cr-1Mo Steel Oxidation Behaviour in Advanced Gas Cooled Reactors ............................................. 25
Aya Shin *, Eleanor Laney, and Jonathan Pearson ............................................................................................... 25
On the Mechanisms and Mitigation of Volcanic Ash Attack on YSZ Thermal Barrier Coatings ............................... 26
Rudder Wu ........................................................................................................................................................... 26
Post-Graduate Student Posters and Presentations
The Effect of Thermal Processing on Secondary Alpha ............................................................................................ 27
Abigail K Ackerman*, David Dye ........................................................................................................................... 27
12
A Study of Superplasticity in Ti-6Al-4V ..................................................................................................................... 28
Enrique Alabort, Roger C. Reed ............................................................................................................................ 28
Degradation of Fibre/Matrix Interfacial Properties due to Fatigue Loading ........................................................... 29
Hidekazu Arai*, Bentang Arief Budiman, Kosuke Takahashi, Kazuaki Inaba, Kikuo Kishimoto ............................ 29
Microtwinning in Nickel-Based Superalloys ............................................................................................................. 30
Daniel Barba1, Enrique Alabort 1, Paraskevas Kontis 2, Antoine Jérusalem 1, Roger C. Reed 1 ............................. 30
An Efficient Interphase Strength Evaluation of Fibre/Matrix Composite by Using Characteristic Length ............... 31
Bentang A. Budiman*, Kosuke Takahashi, Kazuaki Inaba, Kikuo Kishimoto ......................................................... 31
Surface Phase Transformation in Austenitic Stainless Steel Induced by Cyclic Oxidation in Humidified Air ........... 32
Mattias Calmunger 1,*,Robert Eriksson 2, Guocai Chai 1,3, Sten Johansson 1, Johan J. Moverare 1 ....................... 32
Oxidation Behavior of a Single Crystal Ni-based Superalloy at Low Service Temperatures .................................... 33
Angelos Evangelou 1,*, Philippa Reed 1, Scott Lockyer 2, Katherine Soady 2 ......................................................... 33
Oxidation of Nickel-based Superalloys: Modelling & Validation ............................................................................. 34
Yilun Gong 1,*, Henrik Larsson 2, Roger Reed 1, 3 ................................................................................................... 34
Ab Initio Study of the Effect of Solute Atoms on The Vacancy Diffusion in Ni-based Superalloys .......................... 35
Kamal Nayan Goswami*, Alessandro Mottura ..................................................................................................... 35
Modelling and Analysis of Porous Core Material for Steel Laminates ..................................................................... 36
Samuel Hammarberg ........................................................................................................................................... 36
Effects of Ti/Nb Ratio on Nanoindentation Hardness in High Strength Ni-based Superalloys ............................... 37
Hiromu Hisazawa 1,*, Fauzan Adziman 2, David J Crudden2, David E.J. Armstrong3, Roger C Reed2 .................... 37
Precipitation of GCP and TCP Phases at Grain Boundaries in Wrought Ni- base Alloys .......................................... 38
Shuntaro Ida *, Satoru Kobayashi, Masao Takeyama ........................................................................................... 38
Regeneration of Chitin using Conventional Organic Solvents and its Functional Gel Membrane ........................... 39
Yuri Iguchi 1,*, Tomokazu Iyoda 1,2, Keiji Nagai 1,2 ................................................................................................. 39
Growth and Collapse of a Single Bubble near a Plate by Spark Discharge in Water ................................................ 40
Akcam Inci*, Inaba Kazuaki, Takahashi Kosuke, Kishimoto Kikuo ........................................................................ 40
The Improving Graphene Transfer by Changing Transfer Variables ........................................................................ 41
Yo Kan 1,2,*, Ella Carlsen-O'Conor 1, Adrian Murdock 1, Christian van Engers 3, Nicole Grobert 1......................... 41
Wave Propagation across Solid-Fluid Interface with Fluid-Structure Interaction .................................................... 42
Tomohisa Kojima*, Kazuaki Inaba, Kosuke Takahashi, Kikuo Kishimoto .............................................................. 42
The Effect of Boron on Grain Boundary Character in a New Polycrystalline Superalloy ......................................... 43
Paraskevas Kontis 1,*, Hanis A. Mohd Yusof 1, Stella Pedrazzini 1, Katie L. Moore 2, Paul A.J. Bagot 1, Michael P.
Moody 1, Chris R.M. Grovenor 1, Roger C. Reed 1 ................................................................................................ 43
A Study on Si Surface Flattening Process and its Effect on Device Characteristics .................................................. 44
Sohya Kudoh*, Shun-ichiro Ohmi** ....................................................................................................................... 44
The Development of New Co-Ni Superalloys ........................................................................................................... 45
Paul Mulvey 1,*, Mark Hardy 2, David Dye 1 .......................................................................................................... 45
Microstructures and Mechanical Properties of ZrC-added Mo-Si-B alloys .............................................................. 46
Shunichi Nakayama*, Kyosuke Yoshimi ................................................................................................................ 46
13
Intergranular Fracture at 800 deg C in Advanced Nickel-based Superalloys ........................................................... 47
Andre A.N. Nemeth*, David J. Crudden, David E.J. Armstrong, Roger C. Reed ................................................... 47
Lifetime Estimation of Heavy-Vehicle Engine Materials .......................................................................................... 48
Viktor Norman 1,*, Peter Skoglund 1,2, Johan Moverare 1 and Daniel Leidermark 3 ............................................. 48
Thermo-mechanical Characterization of a Nickel-based Superalloy ....................................................................... 49
Lluís Pérez Caro 1,2,*, Eva-Lis Odenberger 1,2,**, Per Thilderkvist 1,***, Mats Oldenburg 2,**** ................................ 49
Material Characterisation for Containment Dimensioning ...................................................................................... 50
Ted Sjöberg 1,*, Jörgen Kajberg 1, Mats Oldenburg 1 ............................................................................................ 50
Fabrication of Al-Cu/pure Al Clad Strips by Vertical-type Tandem Twin-roll Casting .............................................. 51
Tomomi Sugiyama 1,*, Yusuke Takayama 1, Yohei Harada 1, Shinji Kumai 1 ......................................................... 51
Effect of Strain Rate and Grain Diameter on Local Deformation Energy of Industrial Pure Iron ............................. 52
Yuji Takeda 1,*, Masatoshi Aramaki 2, Osamu Furukimi 2, Rintaro Ueji 3, Takashi Muzuguchi 4 ........................... 52
Synthesis of Well-defined Functional Polymer Particles by Living Dispersion Coordination Polymerization of
Allene Derivatives .................................................................................................................................................... 53
Akira Yamauchi 1,*, Takayuki Omura 2, Yoshiyuki Oguchi 2, Hiroshi Yamauchi 2, Hiroki Nishiyama 1, Shinsuke
Inagi 1, and Ikuyoshi Tomita 1 ............................................................................................................................... 53
In-situ Tensile Deformation Behaviour near Grain Boundary with and without Laves Phase in Novel Fe-Cr-Ni-Nb
Steels at 1073 K ........................................................................................................................................................ 54
Mari Yoshihara*, Masao Takeyama ...................................................................................................................... 54
14
Effects of Irradiation on Structural Nuclear Alloys
David E.J Armstrong
Department of Materials, University of Oxford, Parks Road, Oxford, UK
[email protected]
Abstract: The effect of irradiation damage on the mechanical properties of structural nuclear
materials is of key concern in both future fission and fusion nuclear reactors. In these the
temperatures and levels of irradiation seen will be considerably high than those in current
fission reactors and as such the effect of radiation damage much be quantified. Due to the
difficulties in working with neutron irradiated samples ion irradiations are a powerful tool for
simulating this damage without the added expense of working with active materials. However
how successfully they perform this task is unclear.
In this talk I will summarise our key findings on relating the effects of radiation damage on
new materials for nuclear reactors, in particular focusing on tungsten alloys for use in fusion
reactors. Tungsten is the key material for plasma facing components, but there is a lack of
fundamental data regarding its behaviour under neutron irradiation. This work will start out
with an overview of tungsten in fusion and move on to discuss ion irradiated samples of
tungsten and tungsten-rhenium-osmium alloys studied using combinations of high temperature
micro-mechanical testing, atom probe tomography and transmission electron microscopy.
Finally initial work on neutron irradiated tungsten will be shown and compared with ion
irradiated samples. The advantages and disadvantages of ion irradiation will be discussed and
future research directions for tungsten alloys indicated.
15
High-Temperature Oxidation of Metals
Shigenari Hayashi
Department of Metallurgy and Ceramics Science, Graduate School of Science and Engineering, Tokyo
Institute of Technology, 2-12-1-S8-3, Ookayama, Meguro-ku, Tokyo, 152-8552, Japan
[email protected]
Abstract: High-temperature oxidation (and/or corrosion) of metals is the phenomenon that
metallic materials degrades at higher temperatures by reaction with mostly gas species, such as
O2, S2, H2O, SO2, C, and N2, so on. Fast reaction of materials with those gas species causes
rapid consumption of the metallic substrate, change in the substrate composition and
microstructure, which decreases mechanical properties of alloys. Moreover, formation of thick
reaction products may also be detrimental for heat-exchanging systems, such as boiler tubes.
Therefor metallic substrate must be protected from high temperature environments. Preventing
high-temperature oxidation is not possible since metals are thermodynamically much unstable
than oxides and sulphides. Therefore protective oxide scale is usually used to reduce the
“oxidation rate” and increase the lifetime of metallic materials at higher temperatures. As
shown in Fig. 1, SiO2, Cr2O3 or Al2O3 scale can be a protective oxide scale to protect heatresistant alloys and coatings, since those oxide scales are very stable and slow growing at
higher temperatures. The protective oxide scale must be a homogeneous layer and formed by
selective oxidation of alloying elements, therefore sufficient amount of Si, Cr and/or Al must
be contained in the alloy. However, higher addition of those elements is usually detrimental for
mechanical properties of alloys, and development of a protective oxide scale with lower
addition of those elements is strongly required. In this presentation, fundamental of hightemperature oxidation will be explained initially and alloy design from high-temperature
oxidation perspective will be discussed.
Keywords: protective oxide scale, oxidation and corrosion, heat resistant alloy.
Figure Protective oxide scales and their temperature capability.
16
Yield and Creep Mechanisms in Superalloys
C.M.F Rae, O.M.M.D. Mésse, N. Tabrizi and Y. Wang-Koh
Materials Science and Metallurgy, Cambridge University, 27 Charles Babbage Road, CB3 0FS, UK
Abstract: The study of superalloys has traditionally focussed on creep in single crystals and
yield in polycrystals, as these properties are most critical for each application. However it is
clear that as the volume fraction of the  of these alloys is increased to improve strength at
increasingly high temperatures, the same mechanisms are seen in both. The strength of
superalloys is associated with coherent ordered precipitates of : in polycrystalline alloys the
emphasis is on the role of the anti-phase boundaries through weak and strongly coupled
dislocations but in single crystal alloys Kear Wilsdorf locking is quoted as the source of the
increasing strength. Although not often a limiting factor in single crystal alloy design, yield is
nevertheless important and is particularly so where stress concentrations result in low cycle
fatigue challenges.
We present observations on yield in a range of commercial single crystal superalloys: CMSX4*, TMS138A, CMSX-10*, and also polycrystalline disc alloys, showing a range of
dislocation mechanisms depending on the stress and the temperature. Some common features
are seen, but also some important differences. Closely paired dislocations forming dipoles in
tests interrupted shortly after the yield point and discus the role these play in determining the
strength of the alloy. At higher temperature we also see creep-like mechanisms involving
stacking faults at around the yield point. These will be compared with observations from high
stress creep and micro-structures seen in samples fatigued around the yield point.
* CMSX-4 and CMSX-10 are registered trademarks of Cannon Muskegon Corporation
Acknowledgement: This work was supported by Rolls-Royce plc and the EPSRC under Grant
Numbers EP/H022309/1 and EP/H500375/1.
17
Role of Physics-based Constitutive Modelling of Metals
for Simulation of Transformative Manufacturing Processes
Fauzan Adziman*, Nik Petrinic, Roger Reed
Solid Mechanics and Materials Engineering Group, Department of Engineering Science,
University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
*[email protected]
Abstract: Constitutive modelling at two different length scales is introduced to accommodate
underlying physical mechanisms of high grade alloy systems subjected to large deformations,
high strain-rates and high temperatures – extreme conditions inherited by transformative
manufacturing processes of gas turbines such as solid-to-solid joining processes and high-speed
machining. The principles of thermodynamics are used as point of departure to formulate the
constitutive models, leading to thermodynamically-consistent model and physically motivated
evolution equations of internal state variables. Key aspects of solid mechanics to stress and
strain formulations are explained; this includes the use of hypo- and hyperelastic formulations,
and incorporation of plastic anisotropy. Numerical integrations of both explicit and implicit
schemes are discussed, along with a multi-scale framework of computational homogenisation
linking micro- to macroscale. Results show integrated physics-based constitutive models with
experiments hold vital roles for effective development of advanced metals by the bottom up
approach – from designing the alloys up to manufacturing, testing and commissioning.
Keywords: physics-based constitutive modelling, manufacturing process, advanced metals.
Acknowledgement: Funding from the Engineering and Physical Sciences Research Council (EPSRC) UK
through grant EP/K028316/1, for the MAST project, is gratefully acknowledged.
Figure. An integrated approach in physics-based constitutive modelling – from mathematical
and materials modelling, to simulation of manufacturing processes and applications.
18
Dynamic Failure of Materials and Structures
Kazuaki Inaba*, Kosuke Takahashi, Kikuo Kishimoto
Department of Mechanical Sciences & Engineering, Tokyo Institute of Technology, 1-3-1 Ookayama,
Meguro-ku, 152-8550, Tokyo Japan
*[email protected]
Abstract: Our study focuses on the response of a fluid-filled tubes under axial impact loading
experimentally, numerically, and theoretically. The goal of our research is to clarify the
interaction mechanism of flexural waves in tube wall and pressure waves in fluid. We used
steel, aluminum, polycarbonate, and composites as specimen tubes and water, slurry, and water
with air bubbles as fluid. The impact of a free-fall piston initiated pressure waves in the fluid
and stress waves in the tube, which is consider to be similar phenomena as water hammer or
explosion in a piping system. The waves are traveling through the fluid-filled tubes and hoop
strains increased when waves arrived at gage locations. From strain signals, we can measure
wave speeds, known as the Korteweg-Joukowsky speeds, from the arrival times. In the classical
theory, the speed depends on the Young’s modulus of tube, bulk modulus of fluid, diameter of
tube, and thickness of tube wall. We confirmed that wave speeds with various specimen tubes
and fluids could be estimated by the classical theory even with composite tubes by some
extensions of the classical theory. The wave speed is important because pressure surge can be
estimated by the Joukowsky pressure calculated by products of the wave speed, density of
fluid, and boundary speed. When the pressure increases, the tube will get damage. With
aluminum tubes and composite tubes, we observed tube damages and raptures. With steel
tubes, large plastic deformations were observed as well as elastic tube deformations by
traveling waves.
Keywords: water hammer, fluid-structure interaction, impact response.
(a)
(b)
(c)
Figure. Damaged and raptured tubes (a) CFRP, (b) GFRP, (c) mild steel.
19
Modelling Methods for Design of New Alloys
Alessandro Mottura
School of Metallurgy and Materials, University of Birmingham
[email protected]
Abstract: Creep deformation mechanisms markedly change with chemistry in the superalloys.
The planar faults observed after creep in Co-based superalloys are dramatically different to the
planar faults observed after creep in Ni-based superalloys. This happens, in part, due to the
effect of chemistry on planar fault energies. In this work, using a variety of modeling methods,
the variation of planar fault energies across wide compositional ranges in multi-component Cobased alloys is investigated. Results are discussed in light of high-resolution energy dispersive
spectroscopy and high-resolution scanning transmission electron microscopy results showing
segregation of elements such as Ta and W to the superlattice intrinsic stacking faults.
Although Ta additions may produce an increase in stacking fault energies, the presence of other
solute elements can lead to synergetic effects, which instead minimize the value of stacking
fault energies. This has ramifications on currently ongoing alloy-design efforts.
Keywords: alloy design, planar fault energies
Figure. A) Superlattice instrisic stacking fault energy calculations in the Co3Al-Co3WCo3Ta pseudo-ternary and b) how the superlattice intrinsic stacking fault energy may vary
with composition. A contour line at 0 mJ/m2 is drawn for clarity. Negative superlattice
intrinsic stacking fault energies correspond to a stabilization of the D019 phase.
20
Thermal Mechanical Fatigue
Johan Moverare
Division of Engineering Materials, Department of Management and Engineering, Linköping University,
SE-581 83 Linköping, Sweden
[email protected]
Abstract: Nickel-based superalloys are designed to withstand extreme conditions of
temperature and loading during operation. Their performance in critical hot gas path
components such as blades and vanes largely limits the durability of modern gas turbines.
Typically, components experience complicated and inter-related thermal and mechanical
loading, especially during engine start-up and shut down. The thermal gradients in conjunction
with mechanical constraints and the time variation of both the temperature and the stresses may
eventually lead to thermal mechanical fatigue (TMF) damage. TMF is also growing in
importance due to the efficiency of modern cooling systems, and the manner in which turbines
and associated turbomachinery are now being operated. Unfortunately, at the present time,
relatively little research has been carried out particularly on TMF of single crystal (SX)
superalloys. In the present work, emphasis will be placed upon describing: (i) the nature of the
testing method, the challenges involved in ensuring that an given testing methodology is
representative of engine conditions (ii) the behaviour of a typical Re-containing second
generation alloy such as CMSX-4, and its differing performance in out-of-phase/in-phase
loading and crystallographic orientation and (iii) the differences in behaviour displayed by the
Re-containing alloys and new Re-free variants such as STAL-15. It is demonstrated that single
crystal superalloys are prone to different degradation mechanisms involving for example
microtwinning, TCP precipitation and recrystallisation.
Keywords: Fatigue, TMF, Nickel-based superalloys, Twinning, recrystalization.
Figure. Microstructure for a single crystal superalloy subjected to OP TMF-loading in the 100750C temperature range showing twinning, TCP-formation and recrystallization
21
Materials at High Strain Rate
Antonio Pellegrino*, Nik Petrinic
Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
*[email protected]
Abstract: The understanding of the physical phenomena governing the response of materials
and structures subjected to extreme thermo-mechanical loading is of paramount importance in
many sectors, particularly in transportation and in defence. The consequences of impact
loading due to collision or explosion are regularly severe, often threatening the lives of people
involved. Hence the desire to conceive new engineering materials and to design optimal
architectures of engineering systems and structures. This process relies on accurate and reliable
experimental methods for the determination of the material response to dynamic loading and on
the integration of experimental and numerical approaches in order to provide better
understanding of the physical phenomena excited by such extreme loading conditions.
The methodology for the determination of rate dependent behaviour of advanced engineering
materials as well as behaviour of specific naturally occurring materials is herein presented.
Emphasis is given to procedures relevant to the characterization of materials presenting
dissimilar responses and occasionally opposite challenges related to the experimental
determination of their properties. Specific attention is given to the characterisation of ductile
metallic alloys. These are subjected, during high rate tensile testing, to severe strain localization
and adiabatic heating, leading to multi-axiality of the stress state and affecting substantially the
effective strain rate. Peculiar experimental techniques relevant to soft, brittle and granular
materials are also assessed.
Moreover the application of full field digital image correlation techniques on ultra-high speed
cameras footage and the optimization of specimen geometries are discussed.
Keywords: Hopkinson Bar, necking, true strain rate
Figure. Strain localization during high strain rate characterisation of ductile metallic alloys
22
Effect of Plastic and Creep Strains on the Microstructural Changes in a
Single Crystal Ni-base Superalloy
Motoki Sakaguchi 1,*, Masakazu Okazaki 2
1. Department of Mechanical Control Engineering, Tokyo Institute of Technology, Japan
2. Department of Mechanical Engineering, Nagaoka University of Technology, Japan
*[email protected]
Abstract: Single crystal Ni-base superalloys have regularly arrayed composite microstructure
consisting of cuboidal gamma prime precipitates surrounded by narrow channels of gamma
matrix. It has been well known that the microstructure changes accompanying with directional
coarsening, so-called rafting, due to the creep stress. Nowadays, several investigations have
indicated that the directional coarsening could occur by a simple plastic pre-strain and a
subsequent thermal aging. In this study, effects of plastic and creep strains on microstructural
changes in a Ni-base single crystal superalloy, CMSX-4, were experimentally and numerically
investigated. Solid cylindrical specimens were subjected to many types combinations of uniaxial plastic strains and creep strains. A series of experiments revealed that the effect of the
plastic and creep strains on the morphological changes were quantitatively different. In order to
rationalize these experimental results, elastic-plastic and creep analysis using FEM were carried
out, taking account of various microstructural factors such as temperature dependence of the
lattice misfit as well as the difference in the inelastic deformation behaviors between gamma
matrix and gamma prime precipitates. The analytical results showed that the morphological
changes were promoted depending on the inelastic strain gap between the matrix and the
precipitates, which was quantitatively different between under the elastic-plastic and the creep
conditions.
Keywords: Ni-base superalloy, single crystal, plastic strain, creep strain, microstructural changes, rafting,
lattice misfit.
23
Manufacture of Ultra-low Segregation Billets to Enable Novel Ni Superalloy
Compositions for Extreme Condition Applications
Atsushi Sato1, Masaki Taneike2, Ikuo Okada2, Patrick S. Grant1,*
1. Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
2. Takasago R&D Centre, Mitsubishi Heavy Industries, 1-1 Shinhama 2-chome, Arai-cho, Takasago,
Hyogo 676-8686, Japan
*[email protected]
Abstract: An arc spray forming process for the manufacture of billets of advanced
metallurgical alloys has been developed that combines continuous atomisation of two
consumable large diameter wires with billet spray forming technology. The new process has
been explored for the manufacture of complex composition polycrystalline nickel-based
superalloy billets for high temperature applications, exploiting the inherent refined and lowsegregation nature of the as-sprayed microstructure. Critically, the possibility of using the spray
formed billets without any additional downstream consolidation processing, as is typically
required, has been studied. Through a series of process innovations and process parameter
optimisation, as-sprayed billets with low and high temperature mechanical properties better
than cast-wrought equivalents have been produced. Key features of the process are: (i)
relatively high metal flow rate of ~0.6 kg/min and current of 500 A to ensure elimination of
layering in the microstructure; (ii) careful on-line control of the deposition chamber atmosphere
to control any oxygen and nitrogen pick-up; (iii) the introduction of an additional secondary
atomiser to control deposition dynamics and to decrease the gas to metal flow rate to ~2.0; and
(iv) the development bespoke post-deposition heat treatments.
Keywords: nickel superalloys, spray forming, manufacture.
24
Overview of 9Cr-1Mo Steel Oxidation Behaviour in Advanced Gas Cooled
Reactors
Aya Shin *, Eleanor Laney, and Jonathan Pearson
Chemistry and CO2 Oxidation Group, Nuclear Generation, EDF Energy, Barnwood, GL4 3RS, UK
*[email protected]
Abstract: EDF Energy operates seven Advanced Gas Cooled Reactors (AGRs) in the UK to
produce electricity. CO2 is used as the coolant gas in the AGRs, and 9Cr-1Mo ferritic steels
(9Cr steels) are extensively used in the tubing for the evaporator and primary superheater
sections. These steels are susceptible to both oxidation and carburisation in CO2 dominated
coolant fluids under the gas pressure of 450-600 psi at 300°C to 540°C. The oxidation process
of 9Cr steels has two stages: a protective regime in which a duplex protective oxide forms and
the oxidation rate reduces with time, and a breakaway oxidation regime, which is characterised
by fast, linear kinetics. The anticipated oxidation behaviour in the AGR operating environment
was protective; however long term accelerated testing suggests that, under plant conditions,
there is a low but finite probability of breakaway oxidation occurring. This can threaten the
operational life of the AGRs, yet while modelled empirically the mechanism of breakaway
oxidation is not fully understood.
The 9Cr-1Mo Steel Carburisation/Oxidation R&D programme (Phase 3) has been ongoing
since 2014. In Phase 3, the primary focus has been on understanding the mechanism of
breakaway oxidation and developing realistic models, which can ultimately improve the current
boiler tube assessment methodology. Currently six UK universities and three industrial partners
are involved in the programme. An overview of the Phase 3 programme will be presented
during the talk.
Keywords: 9Cr-1Mo Steels, Oxidation in CO2, Advanced Gas Cooled Reactor, Nuclear.
25
On the Mechanisms and Mitigation of Volcanic Ash Attack on YSZ Thermal
Barrier Coatings
Rudder Wu
National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
Abstract: Yttria stabilized zirconia (YSZ) made thermal barrier coatings (TBCs) have been
widely utilized in commercial aero engines for decades. Unlike the injection of airborne
particles forming calcium-magnesium-alumino-silicate (CMAS) on TBCs, which has been
widely investigated, the implications of volcanic ash deposition on TBCs are not well
understood. Previously, it has been demonstrated that volcanic ash readily reacts with alumina
around 1310°C, forming anorthite (CaAl2Si2O8), magnetite (Fe3O4), and spinel
(Al1.75Mg0.889Mn0.351O4) as reactive products, having melting temperatures above that of the
volcanic ash.
The present study continues to explore the possibility of using aluminum based oxides and
alumina doped YSZ in the reaction with volcanic ash to form compounds with melting
temperatures higher than the typical service temperatures of TBCs. I call this the ‘meltingtemperature engineering’ approach to mitigate melting induced penetration of volcanic ash in
TBCs.
Keywords: thermal barrier coatings (TBCs), volcanic ash, CMAS.
Figure. DTA results showing that volcanic ash reacts with alumina to form compounds with
higher melting temperatures
26
The Effect of Thermal Processing on Secondary Alpha
Abigail K Ackerman*, David Dye
Department of Materials, Imperial College, London,
*[email protected]
Abstract: Ti-6Al-2Sn-4Zr-6Mo-0.1Si (Ti6246) is widely used in high temperature
applications, such as high pressure compressor discs in gas turbine engines, due to its high
specific strength, good corrosion resistance and low density. Its complex Witmanstätten
microstructure is thought to be key in the resulting properties of the alloy. Secondary alpha
growing within the surrounding beta matrix is of particular interest, as it is thought that the
presence of this particular phase gives Ti6246 its high strength and good fatigue properties. The
growth of secondary alpha is predominantly controlled by stages of thermomechanical
processing. A cooling rate of 10°min-1 was applied from above the beta transus, with
microstructures being fixed at a variety of temperatures via water quench. The resulting
microstructures were then investigated using optical microscopy, scanning electron microscopy
and electron backscattered diffraction, with a range of volume fractions of primary and
secondary alpha being presented. Samples quenched at higher temperatures showed
predominantly grain boundary alpha with little to no secondary alpha growth. Samples
quenched at lower temperatures presented the final Widmansätten microstructure. It is thought
that this is due to the amount of supersaturation that occurs during the processing, as presented
by Semiatin et al. [1].
References
[1] S.L. Semiatin, S.L. Knisley, P.N. Fagin, D.R. Barker, F.Zhang. Microstructure Evolution during
Alpha-beta Heat Treatment of Ti-6Al-4V Metall and Mat Trans A Metallurgical and Materials
Transactions A, 34.10 (2003): 2377-386.
27
A Study of Superplasticity in Ti-6Al-4V
Enrique Alabort, Roger C. Reed
Department of Engineering Science, University of Oxford, Parks Road, Oxford, UK
Abstract: Superplasticity is vital in many industrial fields — medical, defense, aerospace,
transport and sports among others — for the fabrication of metallic components of complex
geometry. The inherent peculiarity of the effect has kept theorists fascinated for many years.
But significant controversy exists concerning the deformation mechanisms which are operative.
In particular, unequivocal evidence that supports precise details of the accommodation process
— whether it is diffusion, dislocation accommodated, a combination of both or some sort of
cooperative grain boundary — is unavailable. Traditionally, surface studies have been used to
characterise superplasticity. These studies have relied in post-mortem observations. However,
novel in-situ testing techniques are potentially significantly more powerful for the study of
high-temperature deformation mechanisms. In this paper, the mechanisms of superplasticity in
Ti-6Al-4V are discussed. In addition, superplasticity is studied under constant strain-rate
conditions; this has allowed the regime of superplasticity to be pinpointed. For design purposes,
this understanding is translated into validated material laws which are accurate and which
capture the relevant phenomena. Microstructurally explicit material laws are proposed based
upon the micromechanical modes of deformation which are shown to be operating. Validated
material laws are then embedded into a numerical model and are used to simulate an
industrially-relevant manufacturing process which is important for the construction of hollow,
lightweight structures which are of significant practical importance for the aerospace sector.
Keywords: superplasticity, Ti-6Al-4V.
28
Degradation of Fibre/Matrix Interfacial Properties due to Fatigue Loading
Hidekazu Arai*, Bentang Arief Budiman, Kosuke Takahashi, Kazuaki Inaba, Kikuo Kishimoto
Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, Tokyo,
152-0033, Japan
*[email protected]
Abstract: Interface of fibre/matrix composite has important role for overall composite
performance as load bearing structures. Evaluation of interfacial properties and influence of
fatigue on interface must be investigated for long–term safety of structures. Unlike matrix and
fibre, fatigue behaviour of fibre/matrix interface is not clear, which leads to complex failure of
composite under fatigue loading. Our group introduced a new method of evaluating interfacial
strength using characteristic length on a stress contour of composite based on continuum
damage mechanics. Capturing of stress contours is conducted by photo elasticity technique.
Degradation of interfacial strength due to fatigue can be obtained by using single fibre
fragmentation test, cyclic loading test and photo elasticity technique. In this study, a carbon
fibre is replaced by a lead pencil because it is easy to obtain stress contours clearly. First, stress
contours are observed when a lead pencil is broken during single fibre fragmentation test. Next,
cyclic loading test is conducted and interrupted before a specimen is broken. Finally, the stress
contours near the same crack are observed again. Characteristic lengths indicating the
interfacial strength are measured from the images of photo elasticity technique before and after
cyclic loading test. Interfacial strength decreased by 68%, from 4.19 MPa to 1.34 MPa due to
fatigue loading.
Keywords: Fatigue, fibre/matrix composite, interfacial properties degradation, single fibre fragmentation.
(a) Before cyclic loading test
(b) After cyclic loading test
Figure. Captured colour near a lead pencil crack
29
Microtwinning in Nickel-Based Superalloys
Daniel Barba1, Enrique Alabort 1, Paraskevas Kontis 2, Antoine Jérusalem 1, Roger C. Reed 1
1. Department of Engineering Science, University of Oxford, Parks Road, Oxford,
OX13PH, UK
2. Department of Materials, University of Oxford, Parks Road, Oxford, OX13PJ, UK
Abstract: The role of creep deformation in the range 700 to 850 °C is assuming greater
importance for nickel-based superalloys. Why? The temperature of the rim of turbine discs
made from these materials can be within this range for significant portions of the mission cycle,
thus affording the possibility of a time-dependent mode of plasticity.
Unfortunately, the stress and temperature-dependence of this mode of deformation is not well
understood yet – fact stated in some of the latest superalloys reviews [1]. For instance, a
microtwinning mode of deformation has been identified [2] which seems to involve a twinningtype shear coupled with a diffusion-type shuffle of atoms in the 𝛾′ phase. Segregation of some
elements to the microtwins has also been observed.
In this paper, a first attempt is made to build models for this coupled displacive/diffusional
mode of deformation. Both semi-analytical and crystal plasticity type models are developed
and compared. Our aim is to address some critical questions: (I) what are the kinetics of this
mode? (II) How does they depend upon the temperature and stress? (III) What are the ratecontrolling steps? (IV) What is the geometry of the microtwins and how do the dimensions
involve? (V) How best to incorporate these ideas into constitutive models suitable for
engineering design?
The modelling is compared critically with results on model single crystal and polycrystalline
alloys, acquired with a new miniatured electro-thermal mechanical simulation device.
Keywords: microtwinning, superalloys, diffusion, plasticity, creep, modelling, phase transformations.
Refs.
[1] R.C. Reed and C.M.F. Rae. Physical Metallurgy of the Nickel-Based Superalloys. Elsevier Ltd, 2014
[2] L. Kovarik, R.R. Unocic, J. Li, P. Sarosi, C. Shen, Y. Wang, and M.J. Mills. Microtwinning and
other shearing mechanisms at intermediate temperatures in Ni-based superalloys. Progress in
Materials Science, 54(6):839–873, 2009
30
An Efficient Interphase Strength Evaluation of Fibre/Matrix Composite by
Using Characteristic Length
Bentang A. Budiman*, Kosuke Takahashi, Kazuaki Inaba, Kikuo Kishimoto
Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama,
Meguro, Tokyo, 152-8550, Japan
*[email protected]
Abstract: Studies on a region between a fibre and matrix composite mostly deduce that
interphase can be formed on the manufacturing process. The interphase which is a threedimensional thin layer has different mechanical properties from the fibre or matrix. Weak
interphase causes ineffective stress transfer and micro defects which could cause poor
performance of the composite as a load-bearing structure. On this study, an efficient evaluation
of interphase strength (to) is proposed by introducing a characteristic length (Lt) in a stress
contour which can be measured experimentally via photoelasticity. A relationship between to
and Lt is expressed by an equation derived from the stress state in the matrix for an isolated
single-fibre crack. Finite element analysis is then conducted in order to validate the equation.
The analysis proves that the relationship can be approximated as a linear function. A singlefibre fragmentation test for carbon fibre-epoxy specimen is conducted to demonstrate Lt
application for evaluating to. The Photoelastic technique is applied to capture a picture of the
stress contour in the matrix. Several colours of the picture are then extracted to HSV values to
form contours which are plotted in a graph (see Figure). Lt is then measured from the stress
contours and an average interfacial strength of 22.1 MPa is successfully obtained.
Keywords: Interphase strength, fibre/matrix composite, stress contour.
Figure. Fibre crack on single-fibre fragmentation test (a) and plotted stress contours (b).
31
Surface Phase Transformation in Austenitic Stainless Steel Induced by
Cyclic Oxidation in Humidified Air
Mattias Calmunger 1,*,Robert Eriksson 2, Guocai Chai 1,3, Sten Johansson 1, Johan J. Moverare 1
1. Department of Management and Engineering, Linköping University, 58183 Linköping, Sweden
2. Siemens AG, Huttenstr. 12, 10553 Berlin, Germany
3. AB Sandvik Materials Technology R&D Center, 81181 Sandviken, Sweden
*[email protected]
Abstract: The formation of α' martensite at the surface of an AISI 304 stainless steel subjected
to cyclic heating in humidified air is reported. The α' martensite formed during the cooling part
of the cyclic tests due to local depletion of Cr and Mn and transformed back to austenite when
the temperature again rose to 650 °C. The size of the α' martensite region increased with
increasing number of cycles. Thermodynamical simulations were used as basis for discussing
the formation of α' martensite. The effect of the α' martensite on corrosion is also discussed.
Keywords: Stainless steel, Thermal cycling, High temperature corrosion
Figure. ECCI-image of the microstructure after 10 thermal cycles between 100 °C and 650 °C
in ~15 mol% water vapour. The image shows the effect of grain boundary diffusion of
Cr, resulting in a thinner outer oxide layer (presumably Fe2O3) indicated by the three
arrows at the α' martensite (BCC) regions. Above the α' martensite there is a Cr-rich
(Cr, Fe)2O3 scale on the metal surface, compared to the inward growing oxides
(presumably a Ni-rich (Cr, Fe, Ni)3O4 and a Ni-poor (Cr, Fe, Ni)3O4 spinel oxides)
next to it.
32
Oxidation Behavior of a Single Crystal Ni-based Superalloy at Low Service
Temperatures
Angelos Evangelou 1,*, Philippa Reed 1, Scott Lockyer 2, Katherine Soady 2
1. Department of Engineering and the Environment, University of Southampton, Highfield Campus,
Southampton, SO17 1BJ, UK
2. E.ON Technologies (Ratcliffe) Limited, Nottingham, NG11 0EG, UK
*[email protected]
Abstract: The oxidation behavior of a single crystal Ni-based superalloy (CMSX-4) has been
studied via Scanning Electron Microscopy image analysis (SEM) and Energy Dispersive
Spectroscopy (EDS). These analyses have been carried out on the plan views and sections of
the oxide scale produced by prolonged exposures in air at 550°C. The oxidation performance of
the alloy was investigated under isothermal static exposure and isothermal exposure under a
sustained, bending, load. The static oxidation kinetics has been assessed using mass change
data from continuous thermo-gravimetric analysis and oxide scale thickness measurements
from high magnification SEM images. The oxide scale was found to follow a sub-parabolic rate
of growth (Figure 1) and broadly consisted of an outer NiO layer with an Al, Cr, Ti, Ta-rich
oxide inner layer. Although there is some evidence of Al-rich oxide for the longer exposure
times, it could not be concluded that the Al2O3 inner layer that is responsible for the higher
temperature oxidation resistance had formed at these temperatures. Figure 2 shows SEM
images of the morphology of the oxides produced under different stress levels. Oxides formed
over high stressed regions were observed to develop internal protrusions up to 1.5μm deep.
These protrusions mainly consisted of an Al, Re – rich oxide while a Ni, Co – rich oxide was
generally observed to form above them.
Keywords: Oxidation, Ni-based superalloy.
Figure 1. Mass change data for CMSX-4 from
isothermal testing at 550°C.
Figure 2. Effect of externally applied stress on the oxide scale morphology: A) Scale formed
over a plastically deformed region (high stress) with internal protrusions B) Scale
formed over a low stress region
33
Oxidation of Nickel-based Superalloys: Modelling & Validation
Yilun Gong 1,*, Henrik Larsson 2, Roger Reed 1, 3
2. Division of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm, SE10044, Sweden / Thermo-Calc Software AB, Sweden
3. Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
*[email protected]
Abstract: As conditions become ever more aggressive in the turbine, it is no longer the case
that creep deformation alone controls component life; environmental effects such as oxidation
and oxidation-assisted cracking are assuming greater importance. But quantitative, physicsbased modelling of oxidation is rare.
In this poster, we will report progress made so far on the construction of computational models
for oxide formation on Ni-Cr-Al system using coupled CALPHAD thermodynamic and
diffusional kinetic approaches. Both cation and anion diffusion within each oxide phase are
critically considered and assessed. The compositional-dependent oxidation kinetics are
discussed.
Keywords: oxidation, thermodynamics, kinetics, CALPHAD
Figure. The outline of current models predicting the oxidation of nickel-based superalloys.
34
Ab Initio Study of the Effect of Solute Atoms on The Vacancy Diffusion in
Ni-based Superalloys
Kamal Nayan Goswami*, Alessandro Mottura
School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
*[email protected]
Abstract: Ni-based superalloys find applications in the high temperature components of the jet
turbine engines owing to their excellent properties under creep conditions. These properties are
heavily influenced by altering the chemical composition in these alloys. In particular, the
addition of small amounts of Re has been seen to dramatically improve the creep lives of Nibased superalloys, such that this is sometimes referred to as the ‘Re effect’. The microstructure
in these alloys consists of high volume fraction of a hard precipitate phase of cuboidal
morphology embedded in a softer matrix phase. At high temperatures, the deformation in these
alloys is restricted to the soft matrix phase and the creep dislocations cannot shear the
precipitates. Gliding dislocations in the matrix phase have to climb at the interface for
deformation to continue. Climb of dislocations is diffusion-controlled and depends on the
absorption and emission of vacancies at the dislocation cores. Slow-diffusing solutes like Re
are expected to hinder the diffusion of vacancies necessary for the dislocation climb. This
hypothesis was tested in the present work from ab initio calculations using analytical
formulations based on Manning’s random alloy model as well as kinetic Monte Carlo
simulations to quantify the effect of solute elements on the vacancy diffusion coefficients (Dv)
in Ni. Results from calculations within dilute limits suggest that slow-diffusing solute atoms do
not reduce the diffusion of vacancies appreciably in these systems. Work is underway to
investigate the effect in non-dilute regimes.
Keywords: Ni-based superalloys; Re-effect; Vacancy diffusion; Ab initio calculations; kinetic Monte Carlo
simulations.
Figure. Vacancy diffusion coefficients at 1373 K as a function of solute concentration in Ni
from kinetic Monte Carlo simulations.
35
Modelling and Analysis of Porous Core Material for Steel Laminates
Samuel Hammarberg
Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, 971 87,
Sweden.
[email protected]
Abstract: In the modern society reduction of energy use is demanded in various sectors of the
industry. Where the common goal is a sustainable society. One sector where this is in focus is
the car industry, where lighter components can reduce energy consumption of vehicles. Thus,
the manufacturing of lightweight car components is of great interest, and methods for creating
these components are desirable.
In this work, the approach is to introduce steel laminates based on ultra-high strength thin steel
sheets with a porous core to reduce weight. Initially the required conditions for simulating
components subjected to crash loading are investigated. Furthermore the required conditions
for simulating the forming of the component will be studied. Thus it is required in the project to
bring forth a material model which can accurately predict forming of the porous material. This
will be an important tool for future development of steel laminate components, and final use of
the component in a vehicle structure.
If the goals of the project are reached it should be possible to reduce the weight of car
components by up to 30 %. Which in its turn will reduce energy consumption of vehicles, thus
leading to a more sustainable society.
Keywords: Steel laminates, lightweight, constitutive modelling.
.
Figure. Forming of laminate.
36
Effects of Ti/Nb Ratio on Nanoindentation Hardness
in High Strength Ni-based Superalloys
Hiromu Hisazawa 1,*, Fauzan Adziman 2, David J Crudden2, David E.J. Armstrong3, Roger C Reed2
1. Department of Materials Science and Engineering, Tokyo Institute of Technology, 4259 J2-61
Nagatsuta-cho, Yokohama, 226-8502, Japan
2. Department of Engineering Science, University of Oxford, Woodstock Road, OX5 1PF, UK
3. Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
*[email protected]
Abstract: Age-hardening behaviours in high strength Ni-based superalloys ABD with varying
Ti/Nb ratio have been studied by nanoindentation. ABD series alloys were developed with the
aim of great balance of mechanical properties and oxidation resistance at high temperature.
Superior mechanical properties use the large volume fraction of ’ precipitates, which make it
sensitive to cooling condition in process of heat treatment. There is much of importance to
evaluate mechanical property of the alloys varying composition with care of cooling rate. The
alloys ABD-D2, D4, and D6 were studied. D2 contains the most Ti and D6 contains the most
Nb with substitution on 1:1. They were cut into 2.5×2.5×1 mm3 small pieces to achieve
temperature homogeneity, solution treated 30˚C above of ’ solvus and carefully cooled with
rate 60 K/min. Aging treatment at 850 ˚C are followed up to 4 h. Nanoindentation test with
strain rate between 0.001 and 1 show similar hardness and modulus but scattering at the early
stage of indentation related to microscopic inhomogeneity, and stabilized at the last. The figure
shows the change in the stabilized nanoindentation-hardness with following heat treatment. The
hardness of all alloys once drops down with solution treatment and increase again with aging.
ABD-D6 with the most Nb alloy shows the best aging-hardenability among the alloys studied.
Nb is known as a better solution hardening element of ’ precipitate than Ti, however hardness
need to be attributed to microstructure, which requires further observation to correlate hardness
characteristics.
Acknowledgement: This research is a collaboration of University of Oxford and Tokyo
Institute of Technology supported by Academy for Co-creative Education of Environment and
Energy Science (ACEEES).
Keywords: superalloy, nanoindentation, heat treatment
Figure. Change in averaged nanoindentation hardness with following heat treatment in
ABD alloys. They were averaged at the last stage of indentation.
37
Precipitation of GCP and TCP Phases at Grain Boundaries in Wrought Nibase Alloys
Shuntaro Ida *, Satoru Kobayashi, Masao Takeyama
Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 Ookayama
Meguro-ku, Tokyo 152-8550, Japan
*[email protected]
Abstract: Wrought Ni base alloys are commonly strengthened by dispersion of coherent GCP
(Geometrically Close-packed) precipitates such as Ni3Al-' (L12) and Ni3Nb-" (D022) within
grain interiors. This strengthening method works for the materials that require relatively shortterm high strength for jet engine components. However, this is not the case for landbase power
components which require long-term creep rupture strength, and grain boundary design is
definitely needed. In this study, we have first investigated the grain boundary precipitation
behaviour of Ni3Nb- phase (D0a), the poorest symmetry among GCP phases, at elevated
temperatures by using model alloys of Ni-Nb-Fe system. The  phase preferentially nucleates
on the grain boundaries at temperatures above the nose of the TTP curve. However, because of
the distinct crystallographic orientation relationship with matrix ({111} //(010), [110]
//<100>), the phase grows toward the grain interiors. Thus, the average area fraction  of 
phase is limited up to 75 %, depending on grain orientation. Therefore, TCP (Topologically
Close-packed) phase such as Laves phase, which has more complex crystal structure, is more
probable and promising for nucleation at grain boundaries. We will show you the results of the
 by using Ni-Nb-Co ternary model alloys having Co2Nb (C15), together with  phase.
Keywords: Wrought Ni-based alloys, GCP phase, TCP phase.
10 mm
Figure. BEIs of GCP Ni3Nb  phase on grain boundary aged at 1423 K/1 h in Ni-12Nb-3Fe.
38
Regeneration of Chitin using Conventional Organic Solvents and its
Functional Gel Membrane
Yuri Iguchi 1,*, Tomokazu Iyoda 1,2, Keiji Nagai 1,2
1. Department of Innovative and Engineering Materials, Tokyo Institute of Technology, 4259-R1-25,
Nagatsuta, Midori-ku, Yokohama, Kanagawa 243-8506, Japan
2. Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of
Technology,4295-S2 -3, Nagatsuta, Midori-ku, Yokohama, Kanagawa 243-8506, Japan
*[email protected]
Abstract: Chitin, poly (N-acetyl glucosamine), is the principal ingredient of insect carapaces,
and shells of crustaceans which accounts for the rigid structure due to the hydrogen bond
between polymer chains. We investigated the mechanical property and the chemical reactivity
of the regenerated chitin gel to utilise the gel as a functional membrane for applications such as
a membrane catalyst. We regenerated chitin gel by using aprotic organic solvent and the
mechanical properties and structure were examined. The chitin gel was highly transparent and
its xerogel had layer structure. We found that the chitin gel crystallise after drying from
powder-XRD analysis. From compression test, chitin gel had a breaking stress greater than
2.5MPa and breaking strain greater than 88%. The breaking stress of chitin gels differed
depending on the solvent, the presence of a partition plate. These results above indicated the
regenerated chitin gel has the anisotropic character after drying.
Keywords: Natural polymer, Chitin, Organogel, Organocatalyst, Membrane reactor, S-S curve.
Figure. Analysis of chitin gel.
39
Growth and Collapse of a Single Bubble near a Plate by Spark Discharge in
Water
Akcam Inci*, Inaba Kazuaki, Takahashi Kosuke, Kishimoto Kikuo
Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
*[email protected]
Abstract: Establishing the interaction between the bubbly liquid and solid boundary is
important in order to estimate flow profile and there have been many investigations on the
bubble behaviour or bubble dynamics near solid boundaries Single bubble dynamics in the
vicinity of a solid boundary submerged in water were studied experimentally. Single bubble
inside a water tank was generated by a spark discharge of capacitor into a couple of copper
wires closing a simple circuit. A circular polycarbonate plate was placed horizontally above
the bubble creation site. Polycarbonate plates with two different thicknesses were tested by
changing the distance between the plate and the creation site. The effects of distance to the
wall and wall thickness on the bubble motion is observed by considering the fluid-structure
interaction. It is shown that motion of the two boundaries during the bubble generation differ
from each other. Jetting behaviour of two cases is also different. During the experiments, it is
seen that direction of the jet is always away from the boundary for the water-air interface. For
PC plate boundaries, jet changes its direction towards to the boundary as the stand-off
parameter decreases. The value of stand-off parameter to change jet direction is around
γ=1.80 and γ=1.20 for 2 mm and 1 mm thick circular plate, respectively. Considering this
behaviour together with the different motion of the plates during the bubble generation, it can
be said that fluid-structure interaction and plate flexibility plays an important role on collapse
motion of the bubble.
Keywords: bubble, fluid-structure interaction, spark-discharge.
40
The Improving Graphene Transfer by Changing Transfer Variables
Yo Kan 1,2,*, Ella Carlsen-O'Conor 1, Adrian Murdock 1, Christian van Engers 3, Nicole Grobert 1
2. Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
3. Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK
*[email protected]
Abstract: Graphene, a single atom thick layer of graphite with a honeycomb structure,
possesses incredible electrical and physical properties which could be exploited in a wide range
of future applications including faster transistors, flexible transparent conducting layers and
more efficient solar cells. Chemical vapour deposition (CVD) is the most promising technique
for producing large area sheets with high conductance as it is low cost, easily scalable, and
readily controllable. However, one key problem that stands in the way of using CVD graphene
is the need for transferring it from its synthesis substrate (e.g. Cu foil) to a target substrate (e.g.
silicon wafers). While significant work has been conducted, for example bubbling transfer or
electrochemical delamination, however, reliable transfer of CVD graphene is still an issue that
needs resolving for graphene to be used in future applications.
We investigated the transfer of CVD graphene from copper foils to silicon wafers using
polystyrene as a supporting layer. Graphene was synthesised using methane and hydrogen at an
elevated temperature in a CVD system. The roughness of the copper foil was varied by using
various etching methods and different foil purities. We varied the thickness of the polystyrene
by spin-coating onto the graphene. In particular, for the most efficient transfer we suggest using
thinner polystyrene and smoother copper foil. Further investigations into the roughness of
silicon support are also planned for the future. Improving our understanding of graphene
transfer will hopefully bring us closer to harnessing its exceptional properties for use in future
devices.
Keywords: graphene, transfer, polystyrene, carbon, CVD, conductance, Si wafer.
Figure. Graphene transfer method from Cu substrate to Si wafer
41
Wave Propagation across Solid-Fluid Interface with Fluid-Structure
Interaction
Tomohisa Kojima*, Kazuaki Inaba, Kosuke Takahashi, Kikuo Kishimoto
Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, 2-12-1-16-5
Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
*[email protected]
Abstract: Fluid-structure interaction is one of the most important phenomena to be clarified
and controlled in many industrial fields. In some problems, interaction mechanism strongly
depends on wave propagation across the interface of solid and fluid. Although many studies
have been conducted about fluid-structure interaction, the mechanism of wave propagation
close to the solid-fluid interface remains unclear. Our aim is to clarify the mechanism of wave
propagation across the solid-fluid interface with fluid-structure interaction and develop the
theoretical model to explain this phenomenon. In this study, we investigated the relation
between the structural movement and incident / transmitted / interfacial pressure waves on the
solid-fluid interface. The results of the experiments indicated that averaged interface pressure
can be estimated by the Joukowsky equation substituting interface velocity derived from the
impact problems of two rigid bodies with fluid’s momentum. It was also confirmed that under
some conditions, cavitation bubbles appeared on the interface so that the continuity assumption
of the interface may not be valid.
Keywords: fluid-structure interaction, impact, elastic-waves, propagation.
Figure. Strain histories.
42
The Effect of Boron on Grain Boundary Character in a New Polycrystalline
Superalloy
Paraskevas Kontis 1,*, Hanis A. Mohd Yusof 1, Stella Pedrazzini 1, Katie L. Moore 2, Paul A.J. Bagot 1,
Michael P. Moody 1, Chris R.M. Grovenor 1, Roger C. Reed 1
2. University of Manchester, Alan Turing Building, Oxford Road, Manchester, M13 9PL, UK
*[email protected]
Abstract: The role of boron in conferring the grain boundary character in a new polycrystalline
superalloy suitable for power generation applications is considered. One boron-free and three
boron-containing variants are studied using a suite of high resolution characterisation
techniques including atom probe tomography (APT), secondary ion mass spectroscopy (SIMS)
and transmission electron microscopy (TEM). The primary effect of boron addition is the
suppression of Cr-rich M23C6 carbide and the formation instead of the Cr-rich M5B3 boride.
The SIMS analysis indicates that the boride particles are distributed uniformly along the grain
boundaries, of length up to 500nm along the grain boundary and thickness 300nm normal to it.
The substantial majority of the boron added resides in the form of the M5B3 boride; some boron
segregation is found at the γ'/M5B3 interfaces but interfaces of other forms such as γ/M5B3,
γ/MC and γ'/MC are not prone to segregation in this way. Creep testing indicates that the
optimum boron content in this alloy is 0.05 at.%.
Keywords: nickel-based superalloys, grain boundaries, borides, mechanical properties.
43
A Study on Si Surface Flattening Process and its Effect on Device
Characteristics
Sohya Kudoh*, Shun-ichiro Ohmi**
Department of Electronics and Applied Physics, Tokyo Institute of Technology, J2-72, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8502, Japan
*[email protected];**[email protected]
Abstract: As the scaling down of Metal–Insulator–Semiconductor Field-Effect Transistor
(MISFET) which is important for electric devices (e.g. mobile phone and computer), the
interface flatness of the gate insulator/Si will significantly affect the device performance. It is
well known that carrier scattering caused by roughness at the gate insulator/Si interface
degrades the carrier mobility [1]. Furthermore, the interface roughness degraded the reliability
and increased the gate leakage current [1,2]. Even for high-k gate insulator which is necessary
for further scaling, the roughness at high-k/Si interface significantly affects the MISFET
characteristics [3,4]. It has been reported that flat Si surface is able to be obtained by annealing
or sacrificial oxidation. Furthermore, the atomically flat surface of Si(100) is able to be
obtained by annealing in Ar or H2 ambient. To obtain atomically flat Si surface by sacrificial
oxidation process, oxidation mechanism at SiO2/Si interface must be clarified. However, the
mechanism of sacrificial oxidation method has not been clearly explained. In my research, I
have investigated the effect of the sacrificial oxidation for Si surface roughness to clarify the
mechanism, and its effect on electrical characteristics of MIS diodes. By the etching of the 100
nm-thick sacrificial oxide formed by thermal oxidation at 1100 degrees Celsius, the surface
Root-Mean-Square (RMS) roughness of Si substrate was reduced from 0.22 nm to 0.07 nm.
Moreover, it has been revealed that the electrical reliability, evaluated by time-dependent
dielectric breakdown (TDDB) measurement, was dramatically improved by reducing Si surface
roughness.
Keywords: Si surface roughness, oxidation process, MIS diode, reliability.
Figure. Reliability of MIS diodes dependence on
flattening process.
Acknowledgements
The authors would like to thank Mr. N. Hatakeyama
and Mr. M. Suzuki of Tokyo Institute of Technology
for their support for this research. The authors also
thank Prof. Emeritus T. Ohmi and Dr. T. Suwa of
Tohoku University, Dr. M. Shimada and Mr. I. Tamai
of JSW-AFTY for their support and useful discussions
for this research.
[1]
[2]
[3]
[4]
References
R. Kuroda, et al., IEEE Trans. Electron Devices., 56, pp. 291-298, 2009.
T. Ohkawa, et al., IEEE Trans. Electron Devices., 48, pp.2957-2959, 2001.
S. Ohmi, IEICE Electron. Exp., 11, No.14, 20142006, 2014.
S. Ohmi, et al., IEEE Trans. Semicond. Manuf. 28, No.3, pp.266-271, 2015.
44
The Development of New Co-Ni Superalloys
Paul Mulvey 1,*, Mark Hardy 2, David Dye 1
1. Department of Materials, Imperial College London, Prince Consort Road, London, SW7 2BP, UK
2. Rolls Royce Plc, Derby, DE24 8BJ, UK
*[email protected]
Abstract: In 2006 Sato et al discovered that cobalt based superalloys with a stable L12 gamma
prime phase were viable using the Co3(Al,W) system. There is now an on-going effort to
develop these alloys with the aim of increasing engine operating temperatures compared to the
current capabilities of nickel based superalloys. V208C & V208D are Co-Ni superalloys, with
nominal compositions of 36Co-35Ni-15Cr-10Al-3W-1Ta and 40Co-29Ni-17Cr-10Al-3W-1Ta
(at%) respectively, produced by hot isostatic pressing and subsequent forging. Both alloys have
displayed extremely stable secondary gamma prime after 2000 hours at 800°C with an
insignificant degree of coarsening. A combined post-forging heat treatment has been developed
firstly to provide initial stabilisation of the gamma prime phase and secondly to form serrated
grain boundaries. The thermal stability and ability to form serrated grain boundaries shows
great promise for the temperature capabilities and creep performance of these alloys.
Keywords: Cobalt, Superalloy, Heat-treatments.
Figure. Example of a serrated grain boundary achieved with heat treatment.
45
Microstructures and Mechanical Properties of ZrC-added Mo-Si-B alloys
Shunichi Nakayama*, Kyosuke Yoshimi
Department of Materials Science, Tohoku University, Sendai, Miyagi, 980-8579, Japan
*[email protected]
Abstract: Recently, our research group has newly developed TiC-added Mo-Si-B alloys for
ultra-high temperature structural applications. In the alloys, the drawbacks of Mo-Si-B ternary
alloys that are relatively high density (~9.5 g/cm3) and poor room-temperature fracture
toughness have been improved without impairing high-temperature strength. However,
understandings why the material properties of the Mo-Si-B-based alloys are improved by the
TiC addition has not advanced yet. Systematic studies are needed to get understandings on
carbide-added Mo-Si-B alloys. In this study, ZrC is added to Mo-Si-B alloys and the
microstructure and mechanical properties of ZrC-added Mo-Si-B alloys are systematically
investigated. Several kinds of ZrC-added Mo-Si-B alloys were prepared by a conventional arcmelting, and heat-treatment at 1800°C for 24 h in an Ar atmosphere was carried out. After heattreatment, constituent phases in the alloys were Mo solid solution (Moss), Mo5SiB2 (T2), ZrC
and/or Mo2B. The density of the alloys measured using the Archimedes’ principle was in the
range of Ni-based superalloys. High-temperature compression tests at 1400°C and four-points
bending tests with a Chevron notch at room temperature were conducted to investigate their
mechanical properties. It was found that high-temperature strength depends on T2, Mo2B and
ZrC volume fractions. On the other hand, room-temperature fracture toughness depends on not
only Moss volume fraction but also ZrC volume fraction. Therefore, it was strongly suggested
in this study that ZrC plays important roles to provide both high-temperature strength and
fracture toughness in the Mo-Si-B-based alloys. Carbide-added Mo-Si-B-based alloys will
show better structural performance by optimizing composition and microstructure.
46
Intergranular Fracture at 800 deg C in Advanced Nickel-based Superalloys
Andre A.N. Nemeth*, David J. Crudden, David E.J. Armstrong, Roger C. Reed
Department of Materials, University of Oxford, Park Rd, Oxford, OX1 3PH, UK
*[email protected]
Abstract: There is significant interest in defining and quantifying the mechanical performance
of polycrystalline superalloys particularly high strength ones produced by powder processing at
temperatures of 800 deg C for turbine disc applications. In part, this is because the outer rims of
a turbine disc, where the locating features for turbine blades can experience such temperatures
during some portion of the mission cycle. In this work, an electro-thermal-mechanical testing
(ETMT) system is employed which is capable of the rapid assessment of the mechanical
properties of commercial superalloys at 800 deg C on an intermediate length scale; it makes use
of miniature testpieces with a very small cross-section of 1x1 mm. Uniaxial test results from
miniaturised tests were found to be in close agreement to conventional full-scale tests. This
finding confirms that the used miniaturized testpieces are of sufficient size to characterise
certain bulk material properties. Miniaturised tests were then applied to study a turbine disc
relevant problem: intergranular oxidation-assisted cracking. Brittle intergranular failure of a
uniaxial test was achieved at 800 deg C by using a slow strain-rate of 0.0001 /s. To interpret the
slow strain-rate test results and to correlate them to effects on the micro-scale, the ETMT
testpieces were further characterised by the preparation of microcantilevers which allowed the
strength of the grain boundary to be assessed. This suite of experimental tools on a small length
scale when combined with high resolution characterisation techniques allow the compositiondependence of the mechanical properties to be elucidated.
Keywords: Electro-thermal mechanical testing; Nanoindentation; Superalloys; Fracture.
47
Lifetime Estimation of Heavy-Vehicle Engine Materials
Viktor Norman 1,*, Peter Skoglund 1,2, Johan Moverare 1 and Daniel Leidermark 3
1. Division of Engineering Material, Linköping University, SE-58183 Linköping, Sweden
2. Scania CV AB, Materials Technology, SE-15187 Södertälje, Sweden
3. Division of Solid Mechanics, Linköping University, SE-58183 Linköping, Sweden
*[email protected]
Abstract: The demands on newly produced heavy-vehicles expressed by the market and by
the society at large are constantly increasing. In particular, the European Union recurrently
formulates new emission standards to limit the European exhaust emission, which in turn
dictates the lowest acceptable limit of the engine efficiency. Consequently, future engines are
expected to operate at higher combustion pressures and temperatures, which will require
significant measures to avoid the reduction of the engine lifetime. This has called for more
time-efficient and sophisticated design methods, based on finite element and lifetime
assessment modelling rather than prototype testing. Accordingly, the purpose of this study is to
develop a lifetime assessment model for engine materials, which is capable of estimating the
effect of superimposed vibrational (HCF) loads. To this end, the present study has investigated
the fatigue life of laboratory specimens subjected to typical engine load conditions; tests
denoted as combined thermo-mechanical and high-cycle fatigue (TMF-HCF) tests. The studied
materials are those commonly employed in different engine components, namely EN-GJL-250,
EN-GJV-400 and EN-GJS-SiMo5-1. It is demonstrated that all materials follow a consistent
pattern involving a material-dependent threshold, when subjected to an increasing HCF load,
see the figure below. In addition, the developed model manages well to predict this trend. The
model is based on Paris law where the crack length is interpreted as an average length of many
small microcracks. It is also assumed that the crack mechanism is the same in the TMF and
HCF cycle.
Keywords: Cast iron, Thermo-mechanical fatigue, High-cycle fatigue, Fatigue crack growth, Life
prediction.
Figure. The effect of the HCF strain range on the fatigue life of EN-GJV-400 compared with
the model.
48
Thermo-mechanical Characterization of a Nickel-based Superalloy
Lluís Pérez Caro 1,2,*, Eva-Lis Odenberger 1,2,**, Per Thilderkvist 1,***, Mats Oldenburg 2,****
1. Forming Group OSAS, Industrial Development Centre in Olofström AB, Vällaregatan 30,
Olofström, SE-293 38, Sweden
2. Division of Solid Mechanics, Luleå University of Technology, University campus - Porsön, Luleå,
SE-971 87, Sweden
*[email protected]
**[email protected]
***[email protected]
****[email protected]
Abstract: Nickel-based superalloys are often used in the hot sections of gas turbine engines
for both military and civil aircrafts due to their mechanical and chemical stability under
extreme conditions i.e. high temperatures, for a long time. In order to save weight and, thereby,
reduce fuel consumption and carbon dioxide emissions, each part of load carrying structures is
made of the most suitable material state, such as sheet metal parts, small ingots and forgings
assembled by welding. High-tech companies have implemented FE-analysis to model the
whole process chain to improve, identify and solve problem areas in an early stage while
minimizing try-outs and modifications in the manufacturing processes or tooling. However, it is
necessary to provide highly accurate data about material, boundary conditions and process
parameters. In this study, uniaxial tensile tests in Alloy 718 were carried out at different
temperatures up to 900°C in order to provide input data for forming simulations in LS-DYNA.
The heating of the samples was done using inductive heating, while the strains on the
specimens were measured using ARAMIS. Dynamic Strain Aging (DSA) appeared between
300°C and 700°C always followed by an audible acoustic emission, which suggests that type C
serrations were present. The results show a decreasing yield stress yet preserved Lankford
coefficients while increasing the temperature. The combination of both high temperature and
serrations demands the development of a sustainable speckled pattern in order to prevent its
progressive loss during the experiments.
Keywords: FE-analysis, Alloy 718, Dynamic Strain Aging, high temperature.
Figure. Hardening curves of Alloy 718 at room temperature and 500°C.
49
Material Characterisation for Containment Dimensioning
Ted Sjöberg 1,*, Jörgen Kajberg 1, Mats Oldenburg 1
1. Division of Mechanics of Solid Materials, Luleå University of Technology, SE-97187 Luleå, Sweden
*[email protected]
Abstract: Increasingly tough environmental goals, such as the ones set up by the clean sky
joint undertaking, are being put on aircrafts in order to reduce emissions. This is leading
aeronautics manufacturers to push materials and structures closer to their limits in order to
increase efficiency and save weight. GKN Aerospace has declared that they will reduce the
weight of their structural engine components by 20%. At the same time the structural
components have to retain their containment capability; that is to prevent damage to the
surrounding structure in the event of released parts in a blade out event. Hence, good
knowledge in the areas of plastic deformation and failure, especially at high strain rates and
elevated temperatures are of great importance.
As part of an on-going research collaboration between GKN Aerospace and Luleå University
of Technology a methodology to characterise material at conditions closer to service condition
has been developed. Specimens of nickel super alloy 718 have been tested up to strain rates of
1000s-1 by using a high speed tensile testing machine. In order to also test the material at
temperatures up to 650 ˚C the machine has been equipped with an induction heater. Using
standard uniaxial tensile test it is possible to evaluate the stress-strain relation only up to
localisation. To determine the full stress-strain relation all the way to failure a method using
digital speckle photography to capture the local strain field in order to calculate a piecewiselinear hardening curve from the global equilibrium equation has been developed at LTU. One
further advantage of using this method is the possibility to get the true stress – true strain
relation in specimens with geometries undergoing non-uniform deformation.
Figure. a) picture from DSP-measurements showing local strain field
b) hardening curves showing the much higher strains reached by using DSP-based evaluation
Acknowledgements:
This project is performed at Luleå University of Technology in collaboration with GKN Aerospace,
Trollhättan. Economic support is supplied by VINNOVA through the NFFP6 project nr 2013-01155.
50
Fabrication of Al-Cu/pure Al Clad Strips by Vertical-type Tandem Twin-roll
Casting
Tomomi Sugiyama 1,*, Yusuke Takayama 1, Yohei Harada 1, Shinji Kumai 1
1. Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Ookayama, Tokyo,
152-8552, Japan
*[email protected]
Abstract: Clad materials consist of layers of different materials which can combine beneficial
bulk properties of one material with advantageous layer properties of another. Vertical-type
tandem twin-roll casting is a novel method of fabricating aluminium alloy clad strips and can
produce three layered clad strips from molten metals directly. It use two vertical-type twin-roll
casters arranged vertically. Figure is a schematic diagram of this method for three-layered clad
strips. A core layer is fabricated by the first twin-roll, lead into the second roll gap and sanded
by solidification shells of clad layers growing from surface of second twin-roll. This method
can reduce processing time and steps compared to the conventional one and has some
additional merits. Previous studies showed that Al-Mn/Al-Si alloy clad strips, which are widely
used as automotive brazing sheets, can be fabricated by this method, but other kinds of clad
strips had not been reported. Consequently, Al-Cu/pure Al clad material used in airplane bodies
was focused on and its fabrication was attempted. Since the melting temperature of clad is
higher than the solidus temperature of core, it was said to be difficult to be made by this
method. As a result, continuous three-layered clad strips had been fabricated successfully.
However, because of high temperature of clad molten metal and decreasing of cooling ability
of rolls during the casting, at the centre of core, solidification was not completed even after the
strip passed the final cooling point. Therefore further study especially about cooling ability of
rolls is still needed.
Keywords: clad material, twin-roll casting, aluminium alloy.
Figure. A schematic diagram of vertical-type tandem twin-roll casting for three layered clad
strips.
51
Effect of Strain Rate and Grain Diameter on Local Deformation Energy of
Industrial Pure Iron
Yuji Takeda 1,*, Masatoshi Aramaki 2, Osamu Furukimi 2, Rintaro Ueji 3, Takashi Muzuguchi 4
1. Department of Material Processing Engineering, Kyushu University
2. Department of Materials Science and Engineering, Kyushu University
3. Joining and Welding Research Institute, Osaka University
4. Faculty of Engineering, Kagawa University
*[email protected]
Abstract: The effects of strain rate (10-3-103/s) and the grain diameter (60 and 169μm) on the
deformation energy of industrial pure iron were investigated by using of load sensing block
type testing machine to revealed the basic knowledge for the increase of the energy absorption.
We used the specimen with gauge length of 6 mm because of the characteristics of the testing
machine. The deformation energy which is the factors for the increase of energy absorbed in
the collision was estimated by the area of load-displacement curves. Figure 1 shows that the
local deformation energy after the maximum load was increased with the strain rate in the
region from 10-3/s to 10-1/s. This increase of the local deformation energy was caused by the
increase of dislocation movement velocity and void growth behavior by high strain rate. The
increase of the grain diameter also caused the increase of the local deformation energy. The
coarsening of grain diameter increased the ligament length of the voids generated from grain
boundaries. These results suggested that large ligament length causes the large local
deformation energy. On the other hand, the effect of the grain diameter on the uniform
deformation energy was not observed. From these results, it was revealed that the increase in
grain diameter of steel is effective to improve the energy absorption property.
Keywords: vehicle collision, strain rate, grain diameter, local deformation energy, industrial pure iron,
tensile test, load-displacement curves, dislocation, voids, grain boundary.
Figure. Relationships between local deformation energy and strain rate, grain diameter for
industrial pure iron.
52
Synthesis of Well-defined Functional Polymer Particles by Living Dispersion
Coordination Polymerization of Allene Derivatives
Akira Yamauchi 1,*, Takayuki Omura 2, Yoshiyuki Oguchi 2, Hiroshi Yamauchi 2, Hiroki Nishiyama 1,
Shinsuke Inagi 1, and Ikuyoshi Tomita 1
1. Department of Electronic Chemistry, Tokyo Institute of Technology, Nagatsuta-cho 4259-G 1-9,
Midori-ku, Yokohama 226-8502, Japan
2. Sekisui Chemical Co., Ltd. Hyakuyama 2-1, Shimamoto-cho, Mishima-gun, Osaka 618-0021, Japan
*[email protected]
Abstract: Monodispersed polymer particles are attractive materials for a wide range of
advanced applications. Recently, we have reported that the
-allylnickel-catalyzed
coordination polymerization of various allene derivatives proceeds in a living fashion also in
protic polar media1) and polymer particles with narrowly dispersed diameter distribution can be
produced under the dispersion polymerization conditions. In this paper, we describe the living
dispersion sequential copolymerization using comonomers having various functional groups
such as substituted allenes and substituted acetylenes to obtain well-defined functionalized
polymer particles (Scheme 1). As a typical example, the dispersion polymerization of
phenoxyallene (1, 100 equiv) was performed at ambient temperature in EtOH. As a result, 1
was consumed quantitatively within several hours to give a suspension of “living” polymer
particles. Then, an OH-substituted allene monomer (2, 20 equiv), an OH-substituted acetylene
monomer (3, 20 equiv), or a bisallene (4, 20 equiv), was added and the post-polymerization
was performed until the second monomer (2-4) consumed completely. The obtained polymer
particles proved to have narrowly dispersed diameter distribution as confirmed by SEM
observations. The post-polymerization of various allene and acetylene derivatives and the
applications of the well-defined functional polymer particles are also described.
Keywords: Allene Derivatives, Living Dispersion Coordination Polymerization, Polymer Particles.
•
HO
Functionalized by
allene derivatives
2
•
OPh
OCOCF3
CuI
1
Ni
PPh3
PVP
EtOH
OH
3
Functionalized
by acetylene
derivatives
Living polymer
particles
O
•
•
O
Scheme 1.
4
Cross-linked
Reference
1) T. Kino, M. Taguchi, A. Tazawa, and I. Tomita, Macromolecules, 39, 7474-7478 (2006).
53
In-situ Tensile Deformation Behaviour near Grain Boundary with and
without Laves Phase in Novel Fe-Cr-Ni-Nb Steels at 1073 K
Mari Yoshihara*, Masao Takeyama
Department of Metallurgy and Ceramics Science, Graduate School of Science and Engineering, Tokyo
Institute of Technology, S8-8 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
*[email protected]
Abstract: A novel austenitic heat resistant steel of Fe-20Cr-30Ni-2Nb (at.%) exhibits excellent
creep rupture strength superior to any other conventional steels and comparable to wrought Nibase superalloys (IN617) at 1073 K. This superior strength is due to the decoration of grain
boundaries by Fe2Nb TCP Laves phase with the area fraction (ρ) higher than 80 %. This
strengthening method is called “Grain Boundary Precipitation Strengthening (GBPS)”. Our
previous research revealed highly misoriented subgrains formed near the grain-boundary region
with no Laves phase particles on the grain boundaries, and suggested that GB Laves phase
suppresses accelerated local deformation during creep, thereby leading to the excellent
strength. Based on those results, Tarigan et al. proposed a model on GBPS mechanism by
taking the local misorientation into account. However, due to a lack of initial orientation, this
model is not sufficient to evaluate the local deformation. In this study, unique attempt has been
made to detect microstructural and orientation change around grain boundary decorated with
and without Laves phase accurately, in terms of newly designed in-situ tensile test machine
operable at 1073K in SEM chamber. The specimen with a gauge portion of 14x3x1 mm was
tested at a strain rate of 8x10-4 /s up to a plastic strain of 0.1. The in-situ EBSD analysis
(Figure) clearly detected highly misoriented regions with respect to the initial grain orientation,
along the uncovered grain-boundary region, even under relatively higher strain rates. The
highly misoriented region becomes more obvious, depending on grain orientations with respect
to loading axis.
Keywords: In-situ observation, grain-boundary precipitation strengthening.
a
b
0º
c
d
7.0º
5 mm
Figure SEIs and corresponding GROD maps showing the orientation change near grain
boundarie during in-situ tensile test at 1073 K; (a) (c) before and at (b) (d) plastic strain of 0.1.
The support of the Grant-in-Aid (JY220215) on Advanced Low Carbon Technology Research and
Development Program (ALCA), Japan Science and Technology Agency (JST) is gratefully
acknowledged.
54
Sponsors
Symposium venue:
Pembroke College,
Oxford, UK
Symposium secretariat
Technical and on-site enquiries:
General enquiries:
Dr Fauzan Adziman
Mrs Karen Bamford
Department of Engineering Science
Begbroke Science Park
Begbroke Hill
Woodstock Road
Oxfordshire, OX5 1PF, UK
Tel: +44 (0)1865 613076
Email: [email protected]
Department of Engineering Science
Begbroke Science Park
Begbroke Hill
Woodstock Road
Oxfordshire, OX5 1PF, UK
Tel: +44 (0)1865 613450
Email: [email protected]
55

here - Department of Engineering Science

Transcription

Similar documents

New Oxford Shopping Center

Northwest HEADWAE honorees named

For your comfort: Complimentary Full Hot Breakfast Buffet

Promote exchanges in the arts and culture based on city diplomacy

The History Behind Oxford Hoist Over 60 years of dedication

memoirs of a geisha

Review of Read with the Stars 2015

Pediatric Patient Delights in Van Donation, Outings