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arXiv · 1305.1435

On the origin and universality of dislocation creation and void nucleation in FCC ductile metals

Wei-Wei Pang·Ping Zhang·Guang-Cai Zhang·Ai-Guo Xu·Xian-Geng Zhao
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Abstract

We clarify via molecular dynamic simulations and theoretical analysis the origin of dislocation creation and void nucleation during uniaxial tensile process in face-centered-cubic (FCC) ductile metals. We show that the dislocations are created through three distinguished stages: (i) Flattened octahedral structures (FOSs) are randomly activated by thermal fluctuations; (ii) The double-layer defect clusters are formed by self-organized stacking of FOSs on the close-packed plane; (iii) The stacking faults surrounded by the Shockley partial dislocations are created from the double-layer defect cluster due to the relative slip of internal atoms. Whereas, the void nucleation is shown to follow a two-stages description: (i) The vacancy strings are first formed by intersection of different stacking faults; (ii) Then the vacancy strings transform into the voids by emitting dislocations. We demonstrate that our findings on the origin of dislocation creation and void nucleation is universal for a variety of FCC ductile metals with low stacking fault energy.

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Wei-Wei Pang, Ping Zhang, Guang-Cai Zhang, Ai-Guo Xu, Xian-Geng Zhao. 2013-05-07. On the origin and universality of dislocation creation and void nucleation in FCC ductile metals. https://arxiv.org/abs/1305.1435

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