Double twin-like crystalline reorientations in Mg single crystals: Molecular dynamics simulations
Double twin-like crystalline reorientations in Mg single crystals: Molecular dynamics simulations
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镁单晶中的双孪晶晶体重新取向：分子动力学模拟
DOI：
10.1016/j.commatsci.2018.04.012
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发表时间：
2018
影响因子：
3.3
通讯作者：
Guo Yafang
中科院分区：
文献类型：
--
作者：
Zu Qun;Tang Xiaozhi;Zhang Huishi;Guo Yafang
用分子动力学方法研究了Mg单晶在拉伸过程中的两种双孪晶再取向。其中一个可近似描述为典型的{1 0 1 <$$> 1}-{1 0 1 <$2}双孪晶，而第一{1 0 1 <$1}孪晶和第二{1 0 1 <$2}孪晶之间的界面呈现由共存的{1 0 1 <$2}孪晶界面和基底/棱柱界面组成的锯齿形外观。另一种是由具有粗糙边界的先前重取向晶体和随后的{1 0 1 <$1}孪晶形成的，而基底/棱柱界面主导重取向晶体之间的边界。这些双孪晶状的晶体再取向是在沿着或靠近[1 2 1 0]轴的张力作用下随机发生的，取向差角约为66°。基体/棱柱界面和孪晶界的迁移对晶体取向和加载方向的关系敏感，导致重取向晶体的湮灭或长大。此外，研究还发现，重取向晶体与基体之间特殊的粗糙晶界的迁移是通过局部原子重排实现的，这有助于双孪晶状重取向晶体的生长。
Two types of double twin-like crystalline reorientations have been observed in the tension of Mg single crystals by molecular dynamics method. One can be approximately described as a typical {1 0 1¯ 1}-{1 0 1¯ 2} double twin, while the interface between the primary {1 0 1¯ 1} twin and the secondary {1 0 1¯ 2} twin shows a zigzag appearance consisting of co-existing {1 0 1¯ 2} twin boundary and basal/prismatic interface. The other is formed by a prior reoriented crystal with a rugged boundary, and a following {1 0 1¯ 1} twin, while the basal/prismatic interface dominates the boundary between the reoriented crystals. These double twin-like crystalline reorientations with misorientation angles of about 66° randomly occur under the tension along or near the [1 2¯ 1 0]-axis. The migration of basal/prismatic interface and twin boundary is sensitive to the relationship of the crystalline orientation and the loading direction, which causes the reoriented crystal annihilating or growing. Moreover, the migration of special rugged grain boundary between the reoriented crystal and the matrix is revealed to be fulfilled by the local atomic rearrangements, which contributes to the growth of double twin-like reoriented crystals.