Synthesis of AlCrFeMnX-based high-entropy alloys using powder metallurgy and their investigation through thermodynamic perspective

High-entropy alloys (HEAs) are synthesized with an aim to develop structural materials with distinctive property or as a potential replacement to conventional alloys in many applications. The thermodynamics and process routes have a huge impact on the properties of these HEA alloys. In this research work, the following HEA systems: AlCrFeMnNi, AlCrCuFeMnNi, and AlCrCoFeMn are synthesized using powder metallurgical route. Sintering temperatures are evaluated based on phase formation temperatures. Permutations of three temperatures, i.e., 650 °C, 700 °C, and 750 °C, and holding time of 4 h, 6 h, and 12 h are used for sintering. Comparison of all the HEAs is made with respect to thermodynamics, phase development, microstructure transition, and their mechanical properties. The relative density of 94% is achieved through cold compaction route of powder metallurgy. The highest hardness value achieved through PM route is around 256HV due to partial diffusion of elements, resulting in partial phase formation.