Study of grain boundary self-diffusion in iron with different atomistic models
Study of grain boundary self-diffusion in iron with different atomistic models
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DOI：
10.1016/j.actamat.2020.02.027
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发表时间：
2020-04-15
期刊：
影响因子：
9.4
通讯作者：
Drautz, R.
中科院分区：
文献类型：
--
作者：
Starikov, S.;Mrovec, M.;Drautz, R.
利用从头计算和不同原子间电位的分子动力学模拟研究了体心立方铁的晶界自扩散。不同模型的组合使我们能够确定沿不同类型gb的自扩散的主要特征。特别是，我们发现对称倾斜GBs中的原子自扩散主要是由自间隙原子驱动的。相比之下，一般gb原子主要通过交换机制扩散，这种机制不涉及特定缺陷，但类似于液体中的扩散。大多数观察到的机制导致沿GBs的自扩散显著增强，而不是在体中的扩散。通过与现有实验数据的比较，验证了仿真结果。(C) 2020材料学报Elsevier Ltd.出版。版权所有。
We studied grain boundary (GB) self-diffusion in body-centered cubic iron using ab initio calculations and molecular dynamics simulations with various interatomic potentials. A combination of different models allowed us to determine the principal characteristics of self-diffusion along different types of GBs. In particular, we found that atomic self-diffusion in symmetric tilt GBs is mostly driven by self-interstitial atoms. In contrast, in general GBs atoms diffuse predominantly via an exchange mechanism that does not involve a particular defect but is similar to diffusion in a liquid. Most observed mechanisms lead to a significant enhancement of self-diffusion along GBs as compared to diffusion in the bulk. The results of simulations are verified by comparison with available experimental data. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.