Abstract

A novel and efficient deformation methodology, viz., hot-rolling–shearing–bending (HRSB), to introduce a large amount of \(\{ 10\bar {1}2\}\) extension twins (ETs) and control the texture of the AZ31 magnesium alloy thin sheet was proposed. Microstructure and texture within various regions of the thin sheet fabricated by the HRSB method were investigated by means of electron back-scattered diffraction measurement. The experimental results indicated that using only single pass of HRSB, grains with c-axis//normal direction (ND) in as-received sheet are nearly twinned totally (about 91% volume fraction of \(\{ 10\bar {1}2\}\) ET), leading to the formation of c-axis//rolling direction (RD) texture component and the disappearance of c-axis//ND texture component. As for the HRS sample which has suffered from rolling–shearing deformation, both a tensile stress component deriving from the shearing deformation and a compressive stress component resulting from the impediment effect of the mould structure are beneficial to activate \(\{ 10\bar {1}2\}\) ET, the volume fraction of which is about 72%. With respect to the HRSB sample which has undergone rolling–shearing–bending deformation, the further increase in volume fraction of \(\{ 10\bar {1}2\}\) ET might be mainly related to the resultant compressive stress of the tensile stress derived from the bending deformation and the compressive stress resulting from the impediment effect of mould structure. It would hinder the activation of \(\{ 10\bar {1}2\}\) ET within twinned areas and promote the migration of existing boundaries of \(\{ 10\bar {1}2\}\) ET into un-twinned areas.

Graphic Abstract

中文翻译：

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热轧-剪切-弯曲加工AZ31镁合金薄板的组织和织构演变

摘要

一种新颖而有效的变形方法，即热轧-剪切-弯曲（HRSB），可引入大量\（\ {10 \ bar {1} 2 \} \）延伸孪晶（ET）并控制提出了AZ31镁合金薄板的织构。通过电子背散射衍射测量研究了通过HRSB方法制造的薄板各个区域内的微观结构和织构。实验结果表明，仅使用一次HRSB，接收到的片材中具有c轴//法向（ND）的晶粒几乎完全成对孪生（\\\ {10 \ bar {1}的体积分数约为91％2 \} \）ET），导致c轴//滚动方向（RD）纹理分量的形成以及c轴// ND纹理分量的消失。对于遭受滚动剪切变形的HRS样品，剪切变形产生的拉应力分量和模具结构的阻碍作用产生的压应力分量都有利于激活\（\ {10 \ bar { 1} 2}}） ET，其体积分数约为72％。对于经历了滚动-剪切-弯曲变形的HRSB样品，\（\ {10 \ bar {1} 2 \} \）的体积分数进一步增加ET可能主要与弯曲变形所产生的拉伸应力和模具结构的阻碍作用所产生的压缩应力所产生的压缩应力有关。这将阻止孪生区域内\（\ {10 \ bar {1} 2 \} \） ET的激活，并促进\（\ {10 \ bar {1} 2 \} \） ET的现有边界迁移到未缠绕的区域。

图形摘要