A finite-temperature coarse-grained atomistic approach for understanding the kink-controlled dynamics of micrometer-long dislocations in high-Peierls-barrier materials
A finite-temperature coarse-grained atomistic approach for understanding the kink-controlled dynamics of micrometer-long dislocations in high-Peierls-barrier materials
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DOI：
10.1557/s43579-022-00238-w
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发表时间：
2022-09
影响因子：
1.9
通讯作者：
Rigelesaiyin Ji;T. Phan;Youping Chen;D. McDowell;Liming Xiong
中科院分区：
文献类型：
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作者：
Rigelesaiyin Ji;T. Phan;Youping Chen;D. McDowell;Liming Xiong
提出了一种基于声子动力学的有限温度粗粒（FT-CG）原子论方法，用于表征高Peierls势垒材料中扭结控制的位错动力学。通过模拟含有约2.3亿个原子的体心立方铁样品中约3 μ m长位错的运动，证明了它的适用性。在μ m长位错上发现了交叉扭结和碎片，其应力低于nm长位错。它们在很大程度上是由高频/短波长声子促进的。FT-CG被证明是第一个可以预测微米长位错的移动性而不会影响其原子级扭结动力学的模型。图形摘要
We present a phonon dynamics-based finite-temperature coarse-grained (FT-CG) atomistic approach for characterizing the kink-controlled dislocation dynamics in high-Peierls-barrier materials. The applicability of it is demonstrated through simulating the motion of a ~ 3 µm-long dislocation in a bcc iron sample containing ~ 230 million atoms. Cross-kink and debris are found on a µm-long dislocation at a lower stress than that on a nm-long dislocation. They are largely promoted by high-frequency/short-wavelength phonons. FT-CG is shown to be a first model of its kind that can predict the mobility of a µm-long dislocation without smearing out the atomic-level kink dynamics on it. Graphical abstract