Dislocation Pattern in Deformation Band and Crack Nucleation in a Fatigued Copper Bicrystal with Perpendicular Grain Boundary
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

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