Localized deformation and hardening in irradiated metals: Three-dimensional discrete dislocation dynamics simulations
Localized deformation and hardening in irradiated metals: Three-dimensional discrete dislocation dynamics simulations
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DOI：
10.1007/s11663-002-0012-7
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发表时间：
2002-04
期刊：
影响因子：
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通讯作者：
T. Khraishi;H. Zbib;T. D. Rubia;M. Victoria
中科院分区：
文献类型：
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作者：
T. Khraishi;H. Zbib;T. D. Rubia;M. Victoria
当辐照时，金属经历显著的内部损伤积累和机械性能的退化。损伤的形式是高数量密度的纳米级缺陷簇（堆垛层错四面体（SFT）或间隙环）。力学性能的改变表现在硬化行为和局部塑性变形中的无缺陷通道。这项工作使用离散位错动力学（DD）来捕捉这些影响。它设置了滑动位错和缺陷簇之间的弹性相互作用的框架，并详细说明了一个计划，为循环unfaulting和吸收到位错。在这里，它表明，SFTs代表较弱的钉扎点的位错运动比母位错环。它也表明，可观的屈服下降可以归因于高密度的缺陷装饰位错。强的障碍物导致铜中的位错不断地双交叉滑移，从而形成无缺陷通道。最后，屈服应力增加与缺陷数密度之间的相关性与实验非常一致。
When irradiated, metals undergo significant internal damage accumulation and degradation of mechanical properties. Damage takes the form of a high number density of nanosize defect clusters (stacking-fault tetrahedrons (SFTs) or interstitial loops). The alteration of mechanical properties is manifested in a hardening behavior and localized plastic deformation in defect-free channels. This work uses discrete dislocation dynamics (DD) to capture these effects. It sets the framework for the elastic interaction between gliding dislocations and defect clusters and details a scheme for loop unfaulting and absorption into dislocations. Here, it is shown that SFTs represents weaker pinning points for dislocation motion than parent dislocation loops. It is also shown that appreciable yield drop can be attributed to high density of defects decorating the dislocations. Strong obstacles cause dislocations in Cu to continually double cross slip causing the formation of defect-free channels. Finally, the correlation between yield stress increase and defect number density is in excellent agreement with the experiment.