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通过对一种镍基单晶合金中温高应力条件下的蠕变曲线的测定和微观组织及断裂后合金中位错组态的衍衬分析,研究中温高应力条件下单晶合金的组织演化及变形特征。结果表明:在中温高应力条件下,该合金的蠕变激活能Q为(462±20)kJ/mol,表观应力指数na=4.34。表明在试验温度和应力范围内,合金具有较好的蠕变抗力。位错组态衍衬分析表明,蠕变期间切入相内的<110>超位错既可在{100}立方体滑移系中运动,也可在{111}八面体滑移系中运动;位错在运动中相遇发生位错反应,形成的超位错可交滑移至{100}立方体滑移面。位于2个不同{100}六面体滑移面的位错在运动中相遇,可发生位错反应,生成的位错可在{111}八面体滑移系中运动。
Through the determination of the creep curve of a nickel-based single crystal alloy under medium temperature and high stress conditions and the diffraction analysis of the microstructure and the dislocation configuration of the alloy after the fracture, the microstructure evolution of the single crystal alloy under moderate temperature and high stress conditions is studied. Deformation features. The results show that under the condition of high temperature and high stress, the creep activation energy Q of the alloy is (462 ± 20) kJ / mol and the apparent stress index na = 4.34. It shows that the alloy has better creep resistance in the range of test temperature and stress. Dislocation configuration analysis shows that the <110> super-dislocations in the incised phase during creep can move both in the {100} cube sliding system and in the {111} octahedral sliding system; The fault encountered in the movement dislocation reaction, the formation of super-dislocation can be submitted to slip to {100} cube sliding surface. Dislocations located on two different {100} hexahedral slip planes meet in motion and dislocation reactions can occur and the resulting dislocations can move in the {111} octahedral slip system.