Microstructure and Properties of AlCoCrFe1.5Ni High Entropy Alloy

A high entropy alloy was prepared by water cooled copper crucible vacuum induction levitation melting, and then annealing heat treatment of the alloy was carried out at 800 ℃, 900 ℃ and 1 000 ℃; Microstructure, hardness and corrosion resistance of the alloy before and after annealing were studied. The results show that, before annealing, the alloy was composed of a single BCC structure and its microstructure was made up of typical equiaxed grain. There were FCC and σ phases precipitated after annealing at 800 ℃. After annealing at 1 000 ℃, the precipitates were BCC and FCC phases, and there was no σ phase. The resistance to high temperature softening of the alloy was good after annealing below 900 ℃, the hardness of the alloy decreased obviously from 518 HV to 400 HV after annealing at 1 000 ℃. The corrosion resistance of the alloy before and after annealing was better than that of 304 stainless steel. With the increase of annealing temperature, the corrosion resistance of the alloy increased gradually. After annealing at 1 000 ℃, the corrosion resistance of the alloy was better than that of 904 stainless steel.