Simulation of the interaction between an edge dislocation and a '100' interstitial dislocation loop in alpha-iron
Simulation of the interaction between an edge dislocation and a '100' interstitial dislocation loop in alpha-iron
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DOI：
10.1016/j.actamat.2008.06.032
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发表时间：
2008-10
期刊：
影响因子：
--
通讯作者：
D. Bacon
中科院分区：
文献类型：
--
作者：
D. Bacon
原子级模拟用于研究 300K α-铁中刃位错与 <100> 间隙位错环的相互作用。系统地研究了不同环位置和伯格斯矢量方向的位错反应，并比较了两种不同原子间势的结果。反应范围广泛且复杂，但可以用伯格斯矢量守恒的常规位错反应来描述。位错脱离后留下的间隙分数从 25% 到 100% 不等。确定了需要施加高应力才能脱离的反应的性质。比较<100>环路、1/2<111>环路和含有相同数量（169）点缺陷的空隙的障碍强度。 Burgers矢量平行于位错滑移面的<100>环比具有倾斜Burgers矢量的<100>和1/2<111>环稍强：空隙比更强的环弱约30%。然而，小空隙比小 1/2<111> 环更强。一些反应的复杂性和障碍强度的多样性对辐照铁中位错行为的连续介质模型的发展提出了挑战。
Atomic-level simulations are used to investigate the interaction of an edge dislocation with 〈100〉 interstitial dislocation loops in α-iron at 300K. Dislocation reactions are studied systematically for different loop positions and Burgers vector orientations, and results are compared for two different interatomic potentials. Reactions are wide-ranging and complex, but can be described in terms of conventional dislocation reactions in which Burgers vector is conserved. The fraction of interstitials left behind after dislocation breakaway varies from 25 to 100%. The nature of the reactions requiring high applied stress for breakaway is identified. The obstacle strengths of 〈100〉 loops, 1/2〈111〉 loops and voids containing the same number (169) of point defects are compared. 〈100〉 loops with Burgers vector parallel to the dislocation glide plane are slightly stronger than 〈100〉 and 1/2〈111〉 loops with inclined Burgers vector: voids are about 30% weaker than the stronger loops. However, small voids are stronger than small 1/2〈111〉 loops. The complexity of some reactions and the variety of obstacle strengths poses a challenge for the development of continuum models of dislocation behaviour in irradiated iron.