通过测定[001]取向单晶镍基合金的蠕变曲线,结合SEM、TEM观察表明,合金中组织结构的变化对蠕变抗力有明显影响。蠕变Ⅰ、Ⅱ阶段,蠕变的微观机制是位错的攀移；蠕变第三阶段,位错大量切入筏状γ′相中,降低了合金的蠕变抗力,发现交替滑移使筏状γ′相扭曲,致使γ′/γ两相界面产生空穴或微裂纹,是蠕变断裂的直接原因。

The microstructure in different creep stages have been observed by means of SEM and TEM.The results showed that the change of microstructure had obvious influence on creep resistance in superalloy.The dislocation climb was the micromechanism of tensile creep in Ⅰ and Ⅱ stages.In creep ternary stage creep resistance decreased as a result of large number dislocation cutting into γ′ rafts.The direct reason of creep fracture was cavity and microcrack produced on γ′/γ phase interface by the interaction of the multi-slip.