Dislocation-dislocation and dislocation-twin reactions in nanocrystalline Al by molecular dynamics simulation
Dislocation-dislocation and dislocation-twin reactions in nanocrystalline Al by molecular dynamics simulation
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DOI：
10.1016/s1359-6454(03)00232-5
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发表时间：
2003-08-15
期刊：
影响因子：
9.4
通讯作者：
Gleiter, H
中科院分区：
文献类型：
--
作者：
Yamakov, V;Wolf, D;Gleiter, H
我们利用多晶塑性的大规模并行分子动力学模拟来解释在30-100 nm的柱状纳米晶Al微结构变形过程中复杂的位错动力学演化过程。我们详细分析了在足够高的应力下位错-位错和位错-孪晶界反应的机制。这些反应导致形成复杂的孪晶网络结构，即由阶梯-棒位错连接的共格孪晶界结构。与最近的实验观察一致，这些孪晶网络可能导致位错堆积，从而引起应变硬化。(C)2003由爱思唯尔科学有限公司出版的Acta Materialia Inc.版权所有。
We use massively parallel molecular dynamics simulations of polycrystal plasticity to elucidate the intricate dislocation dynamics that evolves during the process of deformation of columnar nanocrystalline Al microstructures of grain size between 30 and 100 nm. We analyze in detail the mechanisms of dislocation-dislocation and dislocation-twin boundary reactions that take place under sufficiently high stress. These reactions are shown to lead to the formation of complex twin networks, i.e. structures of coherent twin boundaries connected by stair-rod dislocations. Consistent with recent experimental observations, these twin networks may cause dislocation pile-ups and thus give rise to strain hardening. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.