Selective Laser Melting (SLM)

Additive manufacturing (AM) with multiple metals
94 days to Christmas...
Emiel Amsterdam
Nederlands Lucht- en Ruimtevaartcentrum – NLR
Netherlands Aerospace Centre – NLR
Holland High Tech Roadmapevent, 22 September 2015
Nationaal Lucht- en Ruimtevaartlaboratorium – National Aerospace Laboratory NLR
Three Ghosts of Christmas
Ghost of Yet to Come Additive Manufacturing:
Star Trek Replicator
2
Three Ghosts of Christmas
Ghost of Past Additive Manufacturing:
Manufacture and add parts together:
- weld
- braze
- ...
Yamaha motor frame
3
Three Ghosts of Christmas
Ghost of Present Additive Manufacturing:
19 fuel nozzles per CFM LEAP engine
(737 max, A320neo)
 number of parts reduced from 18 to 1
 25% lighter than its predecessor
 5x higher durability vs. conventional manufacturing
4
Selective Laser Melting (SLM)
laser
powder
build plate
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Selective laser melting (SLM)
 SLM Solutions 280 HL



powder bed
two lasers
low deposition speed => small details
Build Chamber
(x/y/z)
280 x 280 x 350
mm3
Laser Power
400
1000 W
Build Speed
20
35
cm3/h
Layer thickness
20 – 75
100
µm
Min. wall
thickness
150
1000 µm
Scan speed
15 m/s
Inert gas
consumption
in operation
Ar/N2
2,5 l/min
6
Selective Laser Melting (SLM)
Fysics:
High speed movie of the SLM process
7
Low Pressure Turbine seal
Inconel 718
leak tight thin walls
cooling holes
8
Aluminium engine inlet part
designed by Aeronamic, manufactured by NLR
9
Are we going to print a plane?
No, only parts
bracket designed and manufactured by Airbus
10
Where should we use AM?
 Short lead time
 Complex parts with a high added value





Low weight
Internal cooling channels or 3D shaped surfaces
Shape optimised, organic structures
Smart structures
Multi-material
NC State University
11
Multi material SLM
Transition types:
Compatible materials
sharp
graded
Incompatible materials
“finger” type
mechanically locked
Metal A
Metal B
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Multi metal SLM
Graded material:
layer build-up
after SLM
after heat treatment
13
Multi metal SLM
 Can we optimize the process parameters so that
the heat treatment time can be minimized?
1
2
1. single line scans
2. multiple line scans
3. multiple line scans for several
layers
3
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Two compatible materials were used
15
Single line scans
 Baseline material process parameters
Inconel 718
SS 316 base plate
elemental map overlay
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Single line scans
Elemental maps:
Fe
Ni
Nb
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Single line scans
Ni maps:
baseline
rescan
slow scan speed
18
Multiple line scans for several layers
Difference in mixing distance:
baseline
Inconel 718
SS 316 base plate
Slow scan speed
19
Next steps
 Make columns with sandwiched layers
 Investigate diffusion heat treatments
 Modelling of the grading SLM process

A-symmetrical process
 Demonstrator
20
Demonstrator part
Heat exchanger
Inconel 718
SS316
Inspired by NASA’s Fission Surface Power system (FSP) NaK heat exchanger
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Ghost of Yet to Come SLM
The NLR will make a proposal for a PPS project that will investigate
multi-metal and metal-ceramic for SLM part production:
 Particle reinforced materials
 Graded metals
 Incompatible materials
Metal Additive Manufacturing Technology Centre (MAMTeC)
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