ADVANCE · ADVANCE: Sophisticated experiments and optimisation to advance an existing CALPHAD database for next generation TiAl alloys

To meet the Clean Sky 2 goals to reduce aircraft noise and CO2 and NOx emissions, an optimised titanium aluminide (TiAl) CALPHAD database is needed. Such a database is an integral step to meet these goals as it can be used in the aviation industry to improve existing alloys and create new alloys important in the manufacture of lightweight turbine engine components. The primary goal of this proposal is to experimentally determine critical binary and ternary phase data for several key systems and to incorporate this information into an existing TiAl thermodynamic database. An additional kinetic database will also be updated and provided at the end of the project. By optimising the phase data, this reduces or eliminates the need to conduct costly trial and error experiments, and ultimately speeds the time to market for the turbine engine components. To achieve the goals of this Call for Proposal, a critical analysis of existing state-of-the-art CALPHAD databases, supplied by partner Thermo-Calc Software AB (TCSAB), identified the missing or unreliable data for several important TiAl systems. Data for these systems will be collected through a series of sophisticated experiments on well-characterised high-purity alloys. The experiments will be carried out by the partners Max-Planck-Institut für Eisenforschung GmbH (MPIE), Helmholtz-Zentrum Geesthacht Zentrum für Material- Und Küstenforschung GmbH (HZG) and Montanuniversität Leoben (MUL), who are all recognised for their long-term and well-documented expertise in preparing and characterising TiAl alloys. At key milestones throughout the project, TCSAB, with the assistance of other partners, will critically evaluate the experimental data and conduct thermodynamic assessments of all the systems under investigation. The final analysis will result in two optimised and advanced CALPHAD databases that can immediately be used for alloy design by MTU Aero Engines, which will contribute to the overall Clean Sky 2 targets.