The study on the interaction between defects and dislocation emission is of significance to predict the behaviors of fracture and plastic deformation in crystalline metals; however, the multiscale interaction mechanism has not been well understood. In this work, based on molecular dynamics simulation and distributed dislocation technique, the interaction mechanism between dislocation emission and a crack or a void is studied at the atomic and continuum scales. The results show that dislocation emission can change the mode of crack growth, i.e., from brittle to ductile, and the emitted dislocations cause crack-tip blunt and decrease stress concentration near the defects. The increment of void growth is completely contributed by dislocation emission, and it can be predicted by the characteristics of dislocation emission. This work reveals the influence mechanism of dislocation emission on failure behaviors and deepens the understanding of the interaction between dislocation emission and defects.

中文翻译：

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单晶铝缺陷生长与位错发射相互作用机制的微观和宏观分析

缺陷与位错发射相互作用的研究对于预测结晶金属的断裂和塑性变形行为具有重要意义；然而，多尺度相互作用机制尚未得到很好的理解。在这项工作中，基于分子动力学模拟和分布式位错技术，在原子和连续尺度上研究了位错发射与裂纹或空隙之间的相互作用机制。结果表明，位错发射可以改变裂纹扩展的方式，即从脆性到韧性，并且发射的位错导致裂纹尖端变钝并降低缺陷附近的应力集中。空洞生长的增量完全由位错发射贡献，可以通过位错发射的特征进行预测。