DZ40M钴基合金的高温内氧化现象

Internal Oxidation of Co-base Superalloy DZ40M at High Temperature

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。

Observing the internal structures of Co-base superalloy DZ40M oxidized in air at 900~1100℃, revealed that an internal oxidation zone forms with the oxidation of Cr mainly at the outer part and Al at the inner part below the external oxidation layer grown on the superalloy at all exposure temperatures. Moreover, the internal precipitating oxide changes its morphology from a granular shape into a needle one gradually with theincrement of oxidation temperature. Besides, the higher the temperature, the wider the total oxidation area, and the more easy and serious the cracking and spalling of the oxide scales during isothermal processes.