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Aerospace applications for 5 axis 3D Printing using Laser Metal Deposition
Case Study: Laser Powder Metal Deposition Manufacturing of Complex Real Parts
Carl Hauser, Principal Project Leader
www.merlin-project.eu
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OUTLINE
• The demonstrator part
• Laser Metal Deposition
• The Challenge
• Equipment and Software
• Results
• Summary
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The Demonstrator Part
• Component: Helicopter engine combustion chamber – Virole (Turbomeca)
• Application: Test bed validation during R&D phase.
• Lead Time: 2 months for conventional manufacture
• Size: 300mm diameter x 90mm tall.
• Material: Inconel 718
• Surface roughness: <20 m RA
Image supplied courtesy of Turbomeca
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The Challenge
• Consistent thin wall (0.8mm ±0.12)
• Long straight wall sections (max 42mm)
• Fillet Radii (R10, R5 and R0.8)
• 90 degree flange (overhangs!)
• Net shape, defect free and <20 microns RA
• Heat distortion ?
• Laser Metal Deposition or Selective Laser Melting ???
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Laser Metal Deposition
• Powder filler material
• CO2 Laser melts filler and substrate
• Strong metallurgical bond
• Low dilution (mixing) with substrate
• Full density weld track
• Large build envelope
• High % powder usage
• Nozzle and/or chamber gas shielding
• Multiple layering techniques for 3D Printing
• Applications: Coatings, repair and rebuild and 3D part manufacture.
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Nozzle Choice
LMD Nozzle images from Fraunhofer ILT
• Powder beam focus ~0.2-0.8mm.
• Laser Power <2KW. • High precision.
• Powder beam focus >1mm.
• Laser Power <6KW. • 3D Contours.
• Powder beam focus >>1.5mm.
• Laser Power <10KW. • Surface Cladding.
Coaxial Multi-Jet Off-Axis
Geometric Complexity
Deposition Rate
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Circular Path Powder Focus Fluctuations
Ideal
Reality
Difficult to fine tune deposition parameters
Good Surface finish
Poor Surface finish
Rotating substrate would be better than moving a nozzle in a circular path!
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Maintaining Powder-gas beam focus on top of weld tracks
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Overhanging Features
LMD has no natural support mechanism for overhanging geometries
40
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Overhanging Features
LMD has no natural support mechanism for overhanging geometries
10 max!
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Overhanging Features
LMD has no natural support mechanism for overhanging geometries
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Overhanging Features
LMD has no natural support mechanism for overhanging geometries
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A Revolution in LMD Manufacturing
LMD Nozzle indexes in +z
Substrate revolves and tips
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Software: Slicing
Slice vector, v, at z0
Slice vector, v, at z1
Required Layer thickness, zh0
1
Substrate
LMD tool path
Ix, Iy, Iz
0
nx, ny, nz
Actual layer thickness at tilt
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Software: Controlling Substrate Tilt
0
zh1-n
0
zh0
LMD nozzle
orientation
Z tool path >zh0
• Slice height is adapted based on tilt of table
• Slice height during a build is constant
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Work piece (stainless steel 304L)
Argon shielding gas @ 1.0 bar and 3.0 litres/min
Powder feed rate 2.5grams/min @ 1.5 bar Argon (3.4 litres/min)
1200mm/min
8.4mm
Laser Power 925W
Powder-gas focus 0.5mm Laser beam focus 0.85mm
z increment 0.19mm per revolution ~ 0.25mm/min
Processing Conditions
15-45 microns IN718 powder
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Automated LMD Manufacture
The Future of NET Shape Manufacturing…………??
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Surface Comparison to CAD
-1.0mm 1.0mm 0.0mm
• Average tolerance 0.244mm from CAD (not including top flange).
• No heat treatments!
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Wall Thickness
0.8mm 0.09
Average – 0.845mm
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Wall Deviation from CAD
5mm Radii - Part removed from substrate
0.8mm Radii - Part removed from substrate
Simulation
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Roundness
66mm height position
5mm Radii - Part removed from substrate
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Summary
• 0.8 ±0.9mm thin wall structure successfully built with 5 Axis LMD.
• Key to success is letting substrate do most of the work.
• Tool path can be modified to correct for geometric distortion
• >99.5% wall density throughout (Mechanical properties being tested > focus is
with corrosion resistance)
• 70% powder efficiency: 700 grams of powder fused in the part and 1.2kg passed
through nozzle.
• Deposition rate ~0.9kg/h (build time reduced from months to 7.5 hours)
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Next Steps
• Fond Demonstrator is currently in final stages of manufacture
(completion December 2014)
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• 400mm x 380mm
• 26 hour build time
• Continuous spiral path
• 2400 rotations
• 1.8Km weld track
• 0.9mm wall thickness
• 4kg of powder (3kg
fused in vase)
• Inconel 718
Rubin Vase
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Acknowledgements and Contact
Dr Carl Hauser
Joining Technologies Group
TWI Technology Centre Yorkshire
Advanced Manufacturing Park, Wallis Way, Catcliffe Rotherham. S60 5TZ, UK
Tel: +44 (0)114 269 9046 E-mail: [email protected]
Web: www.twi-global.com
www.merlin-project.eu
