Deformation-twin-induced grain boundary failure
Deformation-twin-induced grain boundary failure
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DOI：
10.1016/j.scriptamat.2011.10.021
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发表时间：
2012
影响因子：
6
通讯作者：
Yongfeng Zhang;P. Millett;M. Tonks;Bulent S. Biner
中科院分区：
文献类型：
--
作者：
Yongfeng Zhang;P. Millett;M. Tonks;Bulent S. Biner
本文提出了形变孪晶诱发晶界失效的机制，并利用分子动力学模拟方法对该机制进行了论证。在110 μ m柱状纳米晶体心立方Mo的拉伸变形过程中，变形孪晶是主要的变形机制。当孪晶靠近晶界时，由于相邻两个晶粒的不相容塑性变形，产生局部应力集中。应力集中的大小随着孪晶变宽而增加，从而通过微裂纹/空隙的成核和聚结导致晶界开裂。
This work presents a mechanism of deformation-twin-induced grain boundary failure, and demonstrates the mechanism using molecular dynamics simulations. Deformation twinning is observed as the dominant mechanism during tensile deformation of 〈110〉 columnar nanocrystalline body-centered cubic Mo. As a twin approaches a grain boundary, local stress concentration develops due to the incompatible plastic deformations in the two neighboring grains. The magnitude of the stress concentration increases as the twin widens, leading to grain boundary cracking by nucleation and coalescence of microcracks/voids.