EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

α+β-TiAl6V4 alloy is the most important titanium alloy for aerospace applications [1,2]. Depending on the thermo-mechanical processing route, a wide range of microstructures can be achieved which differ in proportion and arrangement of the α- and β-phase and the type of transformed β-phase. The microstructures in turn have a decisive effect on the resulting mechanical properties [3]. Since conventional processing is quite time-consuming for the majority of applications and further requires protective gas atmosphere, there is a general interest in shortening processing steps and avoiding the need of α-case protection measures.
In this work, the focus is set on studying the effects of short-time heat treatments on microstructure and mechanical properties of TiAl6V4 sheet metal. The effects of a) solution treatment temperature (below the β transus temperature) and time, b) cooling rate and c) annealing temperature and time are investigated. Samples were heat treated in ambient atmosphere to produce different STQ (solution treated and quenched) and STA (solution treated annealed) states. Microstructures were analyzed by means of scanning electron microscopy and Image J was used as image analysis tool to quantify the proportions of phases. Mechanical properties were determined by hardness and tensile testing at room temperature.
It turned out, that the deformation behavior in tensile testing of TiAl6V4 sheet metal is significantly influenced by the applied STQ or, respectively, STA processing parameters. In case of the most promising STA state, the strength can be significantly increased compared to the initial state while ductility remains in the same range. These observations are very promising for further studies and potential future applications.
The investigations are part of the BMWi-funded joint project TISTRQ. Within this project the Chair of General Materials Properties of the FAU Erlangen-Nürnberg cooperates with the partners Heggemann AG and Dynamore Materials Competence Center.