作　　者： ; ; ; ; ;

机构地区： 东北大学材料与治金学院材料各向异性与织构工程教育部重点实验室

出　　处： 《稀有金属材料与工程》 2012年第3期432-436,共5页

摘　　要： 通过拉伸试验研究了GH690合金从298～623K的变形行为,用光学显微镜、扫描电镜和透射电镜观察了变形组织。结果表明,合金在298K拉伸时能够通过孪生协调变形,生成的形变孪晶阻碍了位错的滑移,从而使合金获得了较高的加工硬化速率,导致合金的强度和塑性较高。随着形变温度的升高,合金通过孪生协调变形的能力降低,变形机制由孪生转变为滑移,滑移产生的加工硬化效应小于孪生,因此合金的强度和塑性随之降低。 The deformation behavior of GH690 alloy from 298 K to 623 K was investigated by tensile tests. The deformation microstructure was observed by OM, SEM, and TEM. The results show that the twinning is the main deformation mechanism for GH690 alloy at 298 K. Under this condition, both high tensile strength and elongation can be obtained because the deformation twins formed in plastic deformation can act as obstacles to dislocations, resulting in obvious work hardening effect. However, as the number of the deformation twins decreases with increasing of the testing temperature, the deformation mechanism of the alloy translates from twinning to dislocation slipping. As the work hardening effect of dislocation slip mechanism is less than that of twinning mechanism, the tensile strength and plasticity of the alloy are decreased with increasing of the testing temperature.

关 键 词： 合金 层错能 形变孪晶 变形机制

领　　域： [金属学及工艺] [金属学及工艺]