Atomic-resolution studies on reactions between basal dislocations and {10(1)over-bar2} coherent twin boundaries in a Mg alloy
Atomic-resolution studies on reactions between basal dislocations and {10(1)over-bar2} coherent twin boundaries in a Mg alloy
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镁合金中基位错与101×2相干孪晶界反应的原子分辨率研究
DOI：
10.1016/j.jmst.2020.06.017
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发表时间：
2021-03-10
影响因子：
10.9
通讯作者：
Yang, Zhiqing
中科院分区：
文献类型：
--
作者：
Su, Huhu;Zhou, Xinzhe;Yang, Zhiqing
用原子分辨方法研究了镁合金中< a（60）>位错与{10（1）over bar 2}共格孪晶界的反应。单个位错-CTB反应产生台阶，残余位错和多个孪晶位错（TD）滑移离开，从而导致TB迁移。{10（1）over bar 2} CTB和由基底< a（60）>位错组成的小角度晶界之间的反应产生基底-棱柱/棱柱-基底界面或不对称倾斜晶界，这取决于TD是否滑移。不仅通过位错-TB反应发射TD可以驱动TB迁移，而且沿着沿着TB的所得台阶或刻面也可以充当TD源以促进TB迁移。我们的研究结果表明，粗糙度或严重损失的位错TB反应引起的局部相干性并不本质上阻碍TB迁移镁合金。位错-TB反应可能是除了晶粒细化和织构改性等技术之外的另一种改善镁合金塑性的可行策略。(C)2021由Elsevier Ltd代表Journal of Materials Science & Technology编辑部出版。
Reactions between basal < a(60)> dislocations and {10 (1) over bar2} coherent twin boundaries (CTBs) in a Mg alloy were studied with atomic resolution. Individual dislocation-CTB reactions produced steps with residual dislocations and multiple twinning dislocations (TDs) gliding away, consequently resulting in TB migration. Reactions between {10 (1) over bar2} CTBs and low-angle grain boundaries composed of basal < a(60)> dislocations created either basal-prismatic/prismatic-basal interfaces or asymmetric tilt grain boundaries, depending on whether TDs gliding away or not. Not only the emission of TDs by dislocation-TB reactions may drive TB migration, but also the resultant steps or facets along TBs can act as TD sources to facilitate TB migration. Our results indicate that roughness or severe loss of local coherency induced by dislocation-TB reactions does not intrinsically impede TB migration in Mg alloys. Dislocation-TB reactions may provide another feasible strategy to improve the ductility of Mg alloys, in addition to other techniques like grain refinement and texture modification. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.