Profuse slip transmission across twin boundaries in magnesium
Profuse slip transmission across twin boundaries in magnesium
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DOI：
10.1016/j.actamat.2016.11.022
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发表时间：
2017-02
期刊：
影响因子：
9.4
通讯作者：
K. Molodov;T. Al-Samman;D. Molodov
中科院分区：
文献类型：
--
作者：
K. Molodov;T. Al-Samman;D. Molodov
在室温和150℃条件下，对随机取向的镁双晶进行了原位SEM单剪切试验。{10¯2}扩展孪晶在晶界处成核，并随着应变的增加而长大。双晶颗粒内部出现直线滑移痕迹，与基底滑移相对应。由于在孪晶边界处发生偏转，这些滑移线很容易继续穿过孪晶。除了基底滑动引起的滑动痕迹外，在150°C时，在孪晶内部观察到额外的滑动线，证明了非基底滑动的激活。在单晶上进行补充试验，观察到通过孪晶边界迁移而形成的孪晶/去孪晶。本文讨论了滑移跨越{10 1¯2}孪晶边界的直接和间接滑移转移、< a>位错向< c+a>位错的转变以及滑移-孪晶相互作用引起的一阶锥体滑移的激活。
In-situ SEM simple shear tests were performed on magnesium bicrystals of random misorientations at room temperature and 150° C.{10 1¯ 2} extension twins nucleated at the grain boundaries and grew with increasing strain. Rectilinear slip traces appeared in the grain interior of the bicrystal which corresponded to basal slip. By deflection at twin boundaries, these slip lines readily continued through the twins. Besides slip traces due to basal slip, additional slip lines were observed inside twins at 150° C that evidenced the activation of non-basal slip. Supplemental tests were performed on single crystals, in which twinning/detwinning via migration of twin boundaries was observed. The obtained results are discussed with respect to direct and indirect slip transfer across {10 1¯ 2} twin boundaries, the transmutation of< a> into< c+a> dislocations and the activation of first-order pyramidal slip as a result of slip-twin interaction.