Microstructure and oxidation behavior of CoCrCuFeNi high entropy alloy at 900 °C
Zilong Wu, Pei Yuwen, Yuanmi Zhang, Chungen Zhou
Abstract
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.