通过蠕变性能测试和组织观察,研究了镍基单晶合金在高温蠕变期间的变形和损伤行为.结果 表明,该合金在1040℃/137 MPa条件下的蠕变寿命为556 h,表现出优异的蠕变抗力.合金在稳态期间的蠕变特性是位错在γ基体中滑移和攀移越过筏状γ\'相.在蠕变后期,合金的变形特征是位错剪切进入筏状γ\'相,剪切γ\'相的位错可以交滑移,形成的Kear-Wilsdorf (K-W)锁可抑制位错的滑移和交滑移.位错的交滑移能够促使筏状γ/γ\'两相的扭曲,致使沿γ/γ\'界面的裂纹萌生及界面断裂,这是合金的损伤和断裂特征.而σ＞η/a被认为是裂纹发生失稳扩展的条件.“,”The deformation and damage behavior of the single crystal Ni-based alloy during elevated temperature creep were investigated through analyzing creep properties and microstructure.The results show that the creep life of Ni alloy under the condition of 1040 ℃/137 MPa is 556 h,displaying an excellent creep resistance of Ni alloy.The creep feature of Ni alloy at steady state is the dislocation glide in γ phase and dislocation climb over the γ\'rafts.In the late stage of creep,the deformation feature of Ni alloy is that the γ\'rafts are sheared by the dislocations of cross-slip,which forms the Kear-Wilsdorf (K-W) locks to restrain the dislocation glide and cross-slip dislocation.The cross-slip dislocations cause the distortion of γ/γ\'rafts,thereby promoting the initiation of cracks along the γ\'/γ interfaces and the interface fracture,which is the damage and fracture features of Ni alloy.The condition of σ＞ η/α is considered as the prerequisite for unstable crack propagation.