High temperature oxidation behavior and mechanism of Al0.3CuCrFeNi2 high-entropy alloy with a coherent γ/γ' microstructure

Abstract In this study, the oxidation behavior of the Al0.3CuCrFeNi2 HEA with a typical coherent γ/γ' microstructure was systematically investigated by the isothermal oxidation tests at 600, 750 and 900 ℃ in air. The results show that the oxidation kinetics of the Al0.3CuCrFeNi2 HEA follow the parabolic law at all three temperatures. As the oxidation temperature increases, the surface segregation of Cu near the grain boundary occurs, leading to different oxidation behavior in the intragranular regions and near the grain boundary regions. The associated formation mechanisms of the oxide scales are proposed and discussed in detail.