An Integrated Computational Materials Engineering (ICME) approach for the design of High-Entropy Alloys (HEAs) for Aeroturbine Propulsion Systems

Advancements in propulsion systems can be accelerated by advances in materials that are candidates for Ni-based superalloy replacements. Current aeroturbine systems commonly employ Ni-based alloys, but inherently limit the performance of such turbines by their melting point (~1455^oC). In order to achieve higher performance engine efficiencies, the materials for aeroturbines must push high temperature stability even hotter. High-entropy alloys (HEAs) are candidates for such applications being that they are single-phase, disordered, and entropically stabilized at high temperatures. Body-centered cubic (BCC) HEAs that contain high contents of refractory elements will serve as excellent potential candidates for aeroturbine materials. However, to predict the compositions, microstructure, properties, and performance of HEAs is a task that is not so easily achieved. The current application of the CALPHAD (Calculation of Phase Diagrams) approach to predict both equiatomic and non-equiatomic, single-phase HEAs will be discussed.