The goal of MMTech was the sustainable introduction of γ-TiAl into aerospace applications through the achievement of a number of primary objectives:
- Reduce the production cost of γ-TiAl parts by 45%
- Reduce production time of γ-TiAl by 55%
- Reduce maintenance costs by 8%
- Target component weight savings of 20-50% using γ-TiAl
- Reduce raw material use over the life of the component by 20%
- Extend component service life by 15%
Reduce production cost by 45% and production time by 55%: the high-energy ball-milled powder will cost around €250 - €350 per kilogram once full-scale production is implemented – a 45% compared to manufacture using gas-atomised powders of a similar composition. RM techniques will lead to reduced material use when making near-net parts and will reduce the number of expensive cutting tools required due to the removal of rough-machining. The active damper will reduce machining costs by 15%. The optimised machine system is expected to increase tool-life by 50%, reduce lubrication costs by 15% and reduce scrap. The RM parameter development and the multi-scale models underpin these results and will be used to determine the optimal microstructure. When tested on the case study parts, partners found 12% cost reduction and 35% time reduction when using AM. Moving to laser-cutting led to a 80% cost reduction and 64% time reduction. A second partner estimated a 15% cost and 2% time reduction.
Reduce maintenance costs by 8%: The reliability and maintainability analysis of the machine tool will reduce maintenance costs by 10%. The use of gamma titanium alloys in place of nickel super-alloys will reduce wear and hence maintenance, whilst increasing component service life. The manufacturing parameters affect the part microstructure which in turn significantly affects the mechanical properties of the final part. The models will indicate the correct parameters to produce optimum microstructures. It was not possible to carry out industrial tests over long enough timescales to determine overall maintenance reduction but partners estimate that by moving to gamma titaniumm they will reduce component maintenance by 9%.
Component weight savings of 20-50%: The selected material variants have a density of 50% that of Nickel superalloy materials, ensuring weight savings around 50%. Further savings can be made through the use of AM and the increased design freedom this brings. Partners found weight savings of 42% - 48% depending on the manufacturing route chosen.
Reduce raw material by 20%: powder production yield was increased to 90-95%, offering a 20% saving in raw material compared to other methods of powder manufacture. Near-net production will reduce the amount of raw material required; this is part dependent. The milling tools to prevent chatter and the self-adaptive process control will reduce the number of parts scrapped during machining. Partners found a reduction in raw material use of 28% to 80% when considering an additive manufacturing production route. When laser-cutting their component, the raw material savings were in excess of 80%.
Extend component life by 15%: modelling and parameter optimisation will allow process parameters to be tailored to create durable, fault-free parts to extend service life. The use of AM will allow novel geometries to be made, reducing areas of stress concentration and will also reduce the number of welds. The improved surface finish achieved through the active damping system will increase service life by 15%. After extensive testing, one partner estimates that the service life of near-net components will improve by 180%; they experienced no change for laser-cut parts. A second partner estimated a service-life increase of 25%.