Journal of Magnesium and Alloys ( IF 17.6 ) Pub Date : 2022-08-01 , DOI: 10.1016/j.jma.2022.07.003 Yuzhi Zhu , Dewen Hou , Kaixuan Chen , Zidong Wang
Textured magnesium alloys usually exhibit anisotropic mechanical behavior due to the asymmetric activation of different twinning and slipping modes. This work focuses on the <c+a> pyramidal slip responses of rolled AZ31 magnesium alloy under two loading conditions, compressive and tensile loading along the normal direction. Under the condition where the compressive loading direction is closely parallel to the c-axis of the unit cell, tensile twinning and basal slips are prohibited, <c+a> dislocations then active and tend to accumulate at grain boundaries and form dislocation walls. Meanwhile, these dislocations exhibit zigzag morphologies, which result from the cross-slip from first-order pyramidal plane to second-order pyramidal plane, then back to first-order pyramidal plane. Under the condition where tensile twins are prevalent, first-order and second-order pyramidal dislocations are favorable to be activated. Both types of dislocations behave climb-like dissociations onto the basal plane, forming zigzag dislocations.
中文翻译:
轧制AZ31镁合金锥体滑移不对称响应的载荷方向依赖性
由于不同孪生和滑移模式的不对称激活,织构镁合金通常表现出各向异性机械行为。这项工作重点研究了轧制 AZ31 镁合金在两种载荷条件下的<c+a>金字塔滑移响应,即沿法线方向的压缩和拉伸载荷。在压缩载荷方向与晶胞c轴紧密平行的情况下,拉伸孪生和基底滑移被禁止,<c+a>位错活跃并倾向于在晶界处积累并形成位错墙。同时,这些位错表现出锯齿形形态,这是由交叉滑移引起的一阶锥体平面二阶锥体平面,然后回到一阶锥体平面。在拉伸孪晶普遍存在的情况下,一阶和二阶锥体位错有利于被激活。两种类型的位错都在基面上表现出类似爬行的解离,形成锯齿形位错。