观察了DZ40M钴基合金在99～1100℃下，经不同时间空气氧化后的内部组织，发现该合金在各曝露温度下均产生了内氧化区，该区靠近外氧化层处主要是Cr的内氧化而离外氧化层较远处主要是Al的内氧化，且随着温度的提高，内氧化物由颗粒状向外状过渡。另外，温度越高，氧化越深入，外氧化层越易开裂和剥落。 The internal microstructure of the DZ40M cobalt-based alloy after air oxidation at 99-1100 ℃ for different periods of time was observed. It was found that this alloy had an internal oxidation zone at each exposure temperature, which was mainly Cr near the outer oxide layer The oxidation is mainly from the internal oxidation of Al and further from the outer oxide layer. As the temperature increases, the internal oxide transitions from granular to extrinsic. In addition, the higher the temperature, the deeper the oxidation, the easier the outer oxide layer to crack and peel off.