Bi偏聚对［001］对称倾侧Cu双晶晶界脆性的影响

EFFECT OF Bi SEGREGATION ON GRAIN BOUNDARY EMBRITTLEMENT OF Cu BICRYSTALS WITH [001] SYMMETRICAL TILT BOUNDARIES

使用定向生长的［００１］对称倾侧Ｃｕ双晶，研究了Ｂｉ偏聚对Ｃｕ双晶断裂行为和晶界脆性的影响．结果表明：Ｃｕ－Ｂｉ双晶的断裂行为和断裂应力强烈地依赖于晶界的取向差，而与晶界的重位点阵密度无关，其晶界脆性取决于未偏聚Ｃｕ双晶晶界的能量．晶界的能量越大，晶界脆性越强．这种依赖关系可由Ｂｉ在不同晶界的选择性偏聚解释．

The effect of Bi segregation at grain boundary on the fracture behaviour and grain boundary embrittlement was studied by using orientationcontrolled Cu bicrystals with [001] symmetrical tilt boundary.The results indicate that the fracture behaviour and fracture stress of Cu-Bi bicrystals depend strongly on the misorientation, and the grain boundary embrittlement is not related to the density of coincidence site lattice of the grain boundary but to the unsegregated grain boundary energy. the higher the grain boundary energy- the stronger the grain boundary embrittlement. The dependence could be explained by considering the boundary-dependent segregation of Bi atoms.