疲劳过程中垂直晶界Cu双晶形变带中位错组态与裂纹形核

DISLOCATION PATTERN IN DEFORMATION BAND AND CRACK NUCLEATION IN A FATIGUED COPPER BICRYSTAL WITH PERPENDICULAR GRAIN BOUNDARY

采用电子通道衬度技术对垂直晶界Cu双晶在疲劳过程中位错组态的演化与裂纹的形核进行了研究,结果表明,形变带中墙结构的间距从形成之初到疲劳裂纹出现始终保持恒定;穿晶裂纹与沿晶裂纹尖端的位错组态均为胞结构;裂纹优先从形变带产生。

The dislocation pattern evolution and crack nucleation in a fatigued copper bicrystal with perpendicular grain boundary (GB) have been investigated by electron channelling contrast (ECC) technique in SEM. The observation results show that in the process from the formation of deformation band (DB) to the appearance of fatigued crack, the spacing between the wall structures in DB keeps constant. The dislocation pattern around the crack tips of transgranular and granular presents misorientation cell structure. The crack preferentially form in DB.