摘要
Rice and Thomson assumed that no dislocation emission takes place from thecrack tip during brittle crack propagation. Experimental observations for Si andFe-Si have shown that dislocations are emitted during cleavage crack propagation.Argon suggested that the transformation from brittle fracture to ductile fracture insilicon is controlled by the number of dislocations emitted from the crack tip ratherthan by dislocation nucleation from the tip. However, Chiao assumed that
基金
Project supported by the National Natural Science Foundation of China.
