Direct observation of twinning–detwinning–retwinning on magnesium single crystal subjected to strain-controlled cyclic tension–compression in [0 0 0 1] direction
Direct observation of twinning–detwinning–retwinning on magnesium single crystal subjected to strain-controlled cyclic tension–compression in [0 0 0 1] direction
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DOI：
10.1080/09500839.2011.617713
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发表时间：
2011-11
影响因子：
1.2
通讯作者：
Qin Yu;Jixi Zhang;Yanyao Jiang
中科院分区：
文献类型：
--
作者：
Qin Yu;Jixi Zhang;Yanyao Jiang
在环境空气中研究了镁单晶在应变幅度为 0.5% 时沿 [0 0 0 1] 方向完全反向拉伸压缩的循环变形。在棱镜平面上对双胞胎进行原位光学显微镜观察。原位表征了孪生-解孪生-再孪生的基本形态演化。发现孪晶的临界解析剪切应力为~2.4 MPa。随着加载循环的增加，孪生-解孪生-重缠的活动耗尽，残余孪晶不断积累。在每个加载周期的解孪过程中，观察到残余孪晶在孪晶边界附近形成，该孪晶边界在之前的拉伸峰值处已完全膨胀。在残余孪晶和基底滑移带的边界上发现了微裂纹。
Cyclic deformation of magnesium single crystal under fully reversed tension–compression along the [0 0 0 1] direction at a strain amplitude of 0.5% was investigated in ambient air. In situ light microscopy of twins was conducted on the prismatic plane. Fundamental morphology evolution of twinning–detwinning–retwinning was characterized in situ. The critical resolved shear stress of twinning was found to be ∼2.4 MPa. With increasing loading cycles, the activity of twinning–detwinning–retwinning exhausted and the residual twins accumulated. During detwinning at each loading cycle, the residual twins were observed to form on the vicinities of twin boundaries which had been fully expanded at the previous tensile peak. Microcracks were found on the boundaries of residual twins and the basal slip bands.