摘要
The oxidation behavior of NiCoCr medium-entropy alloy was investigated at 800 °C in various oxygen pressures from 10 to 10 5 Pa. The results showed that the oxidation kinetics of NiCoCr followed the parabolic rate law, regardless of oxygen pressure. The oxidation rate constants of the alloy steadily increased with increasing oxygen pressure. The oxidation mechanism of the MEA was mainly controlled by outward cation diffusion to form an exclusive Cr 2 O 3 layer although minor amounts of Co- or Ni-Cr spinels were observed at PO 2 = 10 5 Pa under TEM analyses. The main diffusing species were doubly- and triply-ionized cation vacancies.