Microstructure and oxidation behavior of CoCrCuFeNi high entropy alloy at 900 °C

CoCrCuFeNi high entropy alloy (HEA) was prepared by vacuum arc melting. The Microstructure and high temperature oxidation behavior of CoCrCuFeNi HEA was studied. The results show that CoCrCuFeNi high-entropy alloy exhibits a dual-phase FCC structure with both a Cu-poor and a Cu-rich phase. The weight gain of the alloy is 2.2mg/cm 2 after oxidation at 900°C for 100 h. The oxidation kinetics followed the two-stage parabolic rate law. Oxidation product formed on the surface of the alloy has three-layer structure. The outer layer, the middle layer and the inner layer are consisted of CuO, (Ni,Co)(Cr,Fe) 2 O 4 spinel oxide and Cr 2 O 3 , respectively. The oxidation mechanism of CoCrCuFeNi high entropy alloy has been discussed.