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将一种镍基单晶高温合金在室温沿不同晶体取向压缩变形,研究了在试样表面形成的滑移线和微观组织的变化。结果表明:这种合金<111>取向试样的屈服强度最高,<001>取向的强度最低,<110>取向的强度居中。<001>和<110>取向的试样在压缩变形过程中主要启动八面体滑移系,其中<110>取向明显观察到双滑移系的开动;而<111>取向的试样则启动了六面体滑移系。基体通道、枝晶、共晶等组织的备向异性,在一定程度上影响不同晶体取向合金的变形特征。<110>取向试样的变形组织中形成了大量的层错,而在其它两个取向的试样中则未观察到。<111>取向变形后基体通道中的位错密度明显高于其它两个取向,这种高加工硬化率使<111>取向具有高的屈服强度。
A nickel-base single crystal superalloy was compressively deformed along different crystal orientations at room temperature to study the changes of slip lines and microstructures formed on the specimen surface. The results show that the yield strength of this kind of alloy <111> orientation sample is the highest, the strength of <001> orientation is the lowest, and the strength of <110> orientation is the center. The specimens with <001> and <110> orientations mainly initiate the octahedral slip system during compressive deformation, of which the onset of the double slip system is clearly observed in the <110> orientation and the specimens with the <111> orientation are activated Hexahedral slip system. The anisotropy of matrix channels, dendrites and eutectics affect the deformation characteristics of different crystal orientation alloys to a certain extent. A large number of stacking faults were formed in the deformed microstructure of <110> oriented specimens, but not in the other two oriented specimens. The dislocation density in the matrix channels after <111> orientation deformation is significantly higher than the other two orientations, and this high work hardening rate gives the <111> orientation a high yield strength.