Alloy development for High Temperature applications using high entropy concept, II

Research Project, 2018 – 2021

In the pre-study project (ALigHT) we successfully implemented the concept of high entropy alloys (HEAs) to modify commercial IN718 superalloy and improve its specific strength at up to 750°C; i.e. up to 21%, 36% and 14% improvement in specific strength at 25°C, 650°C and 750°C, respectively, compared to the reference alloy. Interestingly, the ductility of some modified alloys was also improved. Despite promising results, the full potential of the concept for development of high performing wrought Ni-based superalloys at high temperature (~750°C) must be understood, as the main goal of the full-scale project (ALigHT II). For reaching to this goal, the relationship between the alloy behavior and microstructural features will be investigated, using advanced characterization techniques. As an additional aspect in production of wrought superalloys, post processing (heat treatment) and hot workability (Gleeble testing at up to ~1200°C) will be examined. Tensile testing at various temperatures (up to ~800°C), followed by thermal stability testing via isothermal ageing at 750°C will help in fulfilling the goal of the project. As another industrial-relevant aspect, the hot corrosion behavior of developed alloys will be compared to the reference alloy. The project aims to be ended with manufacturing a simplified demonstrator, in order to show the potential and primary application of such alloys.