Laser Additive Manufacturing as a Key Enabler for the Manufacture of Next Generation Jet Engine Components - Technology Push EU Project Merlin New Challenges and Perspectives for LAM Processes Carl Hauser, TWI
Contents Additive Manufacturing of Metal Components A Summary of Additive Manufacturing in Aerospace The Drivers The Technology Limitations The Technology Push: The MERLIN Project Some Aspects From the MERLIN Work Programme Build Rate NDT Inspection Laser Metal Deposition Demonstration Summary
What is Additive Manufacturing? From CAD to Tool Path to Component Manufacture
Laser/Metal AM Technologies Laser Metal Deposition with Powder (LMD-p) Laser Metal Deposition with Wire (LMD-w) Selective Laser Melting (SLM) LMD-w LMD-p SLM
Metal Components by Additive Manufacture
Additive Manufacturing in Aerospace Images Courtesy of MTU, Rolls Royce and Turbomeca
The Drivers Freedom of design: New or optimised light-weight complex shaped structures (e.g. lattice structures). Processing of Light-weight materials: Such as titanium alloys. Materials Processing: Nickel and Titanium super alloys. e.g. MAR M 247 which work hardens making it difficult to machine >>>> difficult to weld due to solidification cracking. Low Production Volumes Low Cost?: High Material Utilisation of expensive materials (>80%?) >>>> Powder recycling validation to reduce further waste. Environment?: No toxic chemicals, reduced materials waste
The Technology Limitations Characteristics LMD-w LMD-p SLM Materials (procedures development) Part Dimensions Part Complexity Limited to materials in wire form Limited only by manipulation system (e.g. 1m high x 2m long). Self supporting (Limited) Large Materials Diversity Limited only by manipulation system (e.g. 1m high x 2m long). Self supporting (Limited) Limited compared to LMD Limited by the process chamber (e.g. 250x250x250mm). Nearly Unlimited Dimensional Accuracy >0.2mm >0.1mm >0.1mm Build Rate 60-130cm 3 /h 5-25cm 3 /h 5-10cm 3 /h* Substrates Conformal Surfaces, Conformal Surfaces, Flat surfaces existing components existing components Roughness (Rz) 30-60µm 60-100µm 30-60µm Layer Thickness >3mm 5mm >0.03 3mm >0.03 0.1mm *commercial systems
The Technology Push The MERLIN Project (currently at month 17 of 48) www.merlin-project.eu
MERLIN Concept MERLIN aims to reduce the environmental impact of air transport using Additive Manufacturing techniques in the manufacture of civil aero engines
Build Rate and Productivity AM is currently to slow for Aero Applications How slow? Can we Benchmark productivity against traditional manufacturing? Build rate is a significant factor affecting productivity. However, build rate is strongly affected by: Part Complexity Resolution Substrate geometry There is no holistic solution to define AM productivity it has to be component specific. Topology optimisation >>> Design for AM manufacture.
Build Rate Selective Laser Melting: Current Build Rate: 5-10cm 3 /h MERLIN Target Build Rate: 50cm 3 /h ILT Current Build Rate: ~35cm 3 /h Constraints: >99.5% Density and suitable Metallurgical Properties Proposed Solution: 1KW SLM system using skin/core scanning strategy. Laser Metal Deposition: Images Courtesy of Fraunhofer ILT Current Build Rate: 60-130cm 3 /h (~1Kg/h) MERLIN Target Build Rate: 400cm 3 /h (~3Kg/h) Commercial Laser Cladding Systems: up to 20kg/h (wire) Constraints: >99.5% Density and suitable Metallurgical Properties Proposed Solution: High powder LMD powder and wire systems (hybrid manufacturing?)
Inline NDT Inspection LUT: Laser Ultrasonic Testing In line inspection process and quality control. Layered manufacturing and LUT will allow detailed inspection for flaws and inclusions during manufacture.
LUT - Validation
LUT Modelling Thin walled structures with and without a hole (inclusion)
LUT Modelling Thin walled Structures Thin walled structures with and without a hole (inclusion)
LMD Demonstration Features found on the exterior of an engine case can generally be represented by three geometries: 1. A rectangular pad, 2. A thin-wall flange shape, and 3. Cylindrical boss shape. All Inclusive: Thermal Distortion Control NDT Inspection Metallographic Inspection Deposition Rate Mechanical testing. Aero casing image Courtesy of VAC
LMD Demonstration Images Courtesy of Turbomeca Dimensions Diameter approx. 350mm Height approx. 90mm Wall Thickness : 0.8mm
Summary Productivity increase (Process Control). Topology optimisation. Powder recycling validation. In-process geometrical and NDT validation. Geometrical Scanning Thermal Management High specification materials process development o Inconel 625/718, 738, MAR M 247, Hastelloy X, Single Crystal Testing and Analysis o Density, surface roughness, metallurgical quality, performance analysis at temperature and pressure Demonstration. o 16 aero demonstrators have been introduced into the MERLIN project
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