Co-based superalloys with the advantages of high melting point, high-temperature mechanical properties, and large resistance under hot corrosion environment are potential candidates for turbine engine components. The isothermal oxidation behavior of Co–Ni–Al-based superalloy with the addition of Mo and Cr in dry air at 1073 and 1173 K was investigated. The results showed that similar three-layer oxides structures were composed of Co-containing oxides, complex oxides rich in Co and Al, and Al2O3 layer formed on both 2Mo and 2Cr Co–Ni–Al-based superalloys, and Mo-containing oxides also e...