Y-Hf co-doped AlCoCrFeNi high-entropy alloy coating with superior oxidation and spallation resistance at 1100 °C

Abstract

The oxidation behavior of Y-Hf co-doped AlCoCrFeNi high-entropy alloy coating (HEA coating) at 1100 °C was investigated and compared with that of conventional Y-Hf co-doped NiCoCrAl alloy coating (CNA coating) in this study. First, the HEA coating exhibits an extremely low oxidation rate with an oxidation rate constant of 1.3 × 10−2 μm2/h, which is 50 % lower than that of CNA coating. Second, the HEA coating shows much better resistance to the oxide scale spallation compared with CNA coating, resulting from the lower oxidation rate and the well suppression of interface rumpling.