New materials for high temperature parts
Dr. Eng. Sergio Durante is a core member of the Consortium MMTECH, a multinational coalition of enterprises focused on the development and application of a new generation of materials for high temperature applications (turbochargers, aerospace turbines, rockets).
The MMTech project is focusing on the development of technologies and methodologies which have the potential to save cost and time across the whole aircraft lifecycle, including design, production, maintenance, overhaul, repair and retrofit. It will investigate the steps needed to certify the new technologies for use on planes. The scientific target is based on the sustainable introduction of titanium aluminide alloys in the gamma phase , known as gamma titanium aluminides or γ-TiAl.
This is a promising material for aerospace (but also high-end automotive) applications because is performs well at the high temperatures found in engines and is lighter than the nickel alloys which are currently in use. However, it is extremely brittle at low temperatures and so is hard to work with.
There are several bottlenecks to the general introduction of γ-TiAl in aerospace and automotive components. The various alloys are currently expensive and are hard to obtain, so machining large block of material is unattractive. Making parts using near-net techniques such a rapid manufacture (RM) uses less material, but comes with its own problems. Powder properties can vary across suppliers and even between batches, meaning that process parameters need to be set for each new build. Near net parts also need machining, but because γ-TiAl is brittle at low temperatures, it is extremely hard to finish-machine the components without producing cracks. MMTECH will develop methods of creating stable, consistent powder batches and investigate adaptive manufacturing techniques which can automatically vary deposition and machining parameters based on information gained during previous parts of the process chain . It will also look into ways of softening the material during processing using lasers to reduce cracking.
Specific advanced tools will be used for the new approach, based on integration of experimental testing and multi-scale modeling. Multi-scale modelling techniques will be applied to the manufacturing route to predict the inherent material properties of the γ-TiAl parts produced with RM and to optimise the laser-assisted machining process for high performance and high-quality production.
These goals will be achieved by meeting a number of technology challenges:
•The production of powders with stable physical properties
•The reduction of rapid manufacturing costs
•The improvement of machining processes •The development of multi-scale models of the manufacturing process chain
Official project link:
MMTECH dissemination event t the famous Cesana Sestriere 2016 hillclimb race, valid for the European Championship