Effect of Annealing on Phase Composition and Microstructure of the CoCrFeNiMnVx (x=0, 0.25, 0.5, 0.75, 1) High Entropy Alloys

Recently developed high entropy alloys (HEAs) have complex chemical composition, however, the relationship between the choice of constitutive elements and their concentration and phase composition and microstructure of HEAs is not fully understood at the moment, as well as the potential effect of annealing on the phase composition of HEAs. In this report, we present data on microstructure of the CoCrFeNiMn-based alloys with different V content in as-solidified state and after annealing at temperatures of 700–1000°C. It is shown that alloying with V results in formation of intermetallic sigma phase in as-solidified state. Annealing has pronounced effect on morphology and volume fraction of sigma phase. The temperature corresponding to maximum volume fraction of sigma phase is shown to be significantly dependent on V concentration.