Generalized stacking fault energy surface mismatch and dislocation transformation
Generalized stacking fault energy surface mismatch and dislocation transformation
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DOI：
10.1038/s41524-021-00660-z
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发表时间：
2021-12
影响因子：
9.7
通讯作者：
Longsheng Feng;M. Mills;Yunzhi Wang
中科院分区：
文献类型：
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作者：
Longsheng Feng;M. Mills;Yunzhi Wang
尽管在过去的世纪中，位错活动的基本规律已经被很好地确立，但我们报道了一种现象，位错转变，它是由两个共存相之间的广义层错能面失配（简称GSF失配）所控制的。通过进行从头算知情的微观相场模拟，我们证明了GSF之间的不匹配的高对称性矩阵相和低对称性沉淀相可以转换成两种不同类型的全位错的阵列时，通过沉淀物剪切矩阵中的相同的全位错的阵列。沉淀物作为一个被动的肖克莱部分源，产生新的肖克莱部分位错，既不是从全位错的解离。这一现象丰富了我们对部分位错成核和位错-沉淀物相互作用的基本理解，提供了额外的机会来定制由低对称性沉淀物相强化的合金中的加工硬化和孪晶过程。
Even though the fundamental rules governing dislocation activities have been well established in the past century, we report a phenomenon, dislocation transformation, governed by the generalized-stacking-fault energy surface mismatch (GSF mismatch for short) between two co-existing phases. By carrying out ab-initio-informed microscopic phase-field simulations, we demonstrate that the GSF mismatch between a high symmetry matrix phase and a low symmetry precipitate phase can transform an array of identical full dislocations in the matrix into an array of two different types of full dislocations when they shear through the precipitates. The precipitates serve as a passive Shockley partial source, creating new Shockley partial dislocations that are neither the ones from the dissociation of the full dislocation. This phenomenon enriches our fundamental understanding of partial dislocation nucleation and dislocation-precipitate interactions, offering additional opportunities to tailor work-hardening and twinning processes in alloys strengthened by low-symmetry precipitate phases.