Impacts of pre-strain on twin boundary mobility of magnesium
Impacts of pre-strain on twin boundary mobility of magnesium
复制标题
预应变对镁孪晶界迁移率的影响
DOI：
10.1016/j.jallcom.2019.152496
复制
发表时间：
2020-03-05
影响因子：
6.2
通讯作者：
Chiba, Akihiko
中科院分区：
文献类型：
--
作者：
Cui, Yujie;Bian, Huakang;Chiba, Akihiko
孪晶界迁移率对镁合金的力学性能有重要影响。在本研究中，通过评价压缩和拉伸过程中屈服应力的变化，以及用原位电子背散射衍射仪观察显微组织，系统地研究了预应变对纯镁TBM的影响。由于较低的位错密度和较少的其他晶界限制，2%压缩应变下纯镁中的小孪晶表现出比前4%和前8%压缩纯镁中的大孪晶更高的TBM。随着预应变的增加，TbM减小的主要原因是位错数量较多，阻碍了孪晶界的运动。这些结果表明，通过预应变改变孪晶尺寸和位错密度是一种有效的热塑性成形方法，为开发新型工业化镁合金提供了依据。(C)2019爱思唯尔B.V.保留所有权利。
Twin boundary mobility (TBM) has significant influences on the mechanical properties of magnesium (Mg). In the current study, the effects of pre-strain on TBM in pure Mg are systematically investigated by evaluating the change of yield stress during compression and tension, and microstructure observations by in-situ electron back-scattered diffraction. Owing to lower dislocation density and less restriction from other boundaries, smaller twins in pure Mg subjected to 2% compressive strain exhibit higher TBM than larger twins in pre-4% and pre-8% compressed pure Mg. Decreased TBM with increasing pre-strain is primarily because of the larger number of dislocations, which impede twin boundary motion. These findings indicate that altering twin size and dislocation density by pre-strain is an effective way to tailor TBM, providing a basis for developing new industrial Mg alloys. (C) 2019 Elsevier B.V. All rights reserved.