不均一超微細粒組織を有するマグネシウム合金の変形機構の解明

我们发现，在拉伸试验过程中，随着应变局域带状组织的形成、扩展和湮灭，脱孪晶在试件尺度上发生。这是在AZ31镁合金中的新发现。此外，我们还认识到AZ31镁合金在脱孪晶过程中表现出微观的不均匀变形，滑移激活也很重要。为了研究为什么表现出显著脱孪晶行为的00O试件表现出与表现拉伸性能一般形状的90O试件不同的拉伸性能，需要研究每个试件的变形行为。因此，我们进行了微观DIC分析，以考察滑移和去孪晶对变形的影响。结果表明，不仅0O试样由于去孪生引起的应变分布是不均匀的，而且90O试样由于滑移变形引起的应变分布也是不均匀的，必须考虑每个试件的滑移行为，才能了解激活了哪种类型的滑移变形，以及为什么应力-应变曲线有如此大的差异。我们研究了预压缩AZ31合金的哪种滑移系统被激活。基面<a>滑移主要在母材和预孪晶区激活。我们还需要研究拉伸变形试件的变形结构，以了解&lt；a&gt；或棱柱滑移是否被激活。

We found out that de-twinning takes place in a specimen scale with formation, propagation, and annihilation of strain-localized banding during the tensile test. This is a new finding in AZ31 Mg alloy. Furthermore, we realized that AZ31 Mg alloy accompanying de-twinnning shows microscopic inhomogeneous deformation due to de-twinning and slip activation is also important. In order to investigate why the 0o specimen showing significant de-twinning behavior shows such different tensile properties in comparison to the 90o specimen showing the general shape of tensile properties, the deformation behavior of each specimen needs to be investigated. Therefore, we conducted a micro-DIC analysis to examine the effect of slip and de-twin on deformation. As a result, we figured out that not only the strain distribution of the 0o specimen was heterogeneous due to de-twinning, but also the strain distribution of the 90o specimen was inhomogeneous due to the slip deformation.The slip behavior of each specimen must be taken into account to understand what kinds of slip deformation are activated and why the stress-strain curve is so much different. We investigated which kinds of slip systems of a pre-compressed AZ31 alloy were activated. Basal <a> slip was mainly activated in the matrix and pre-twinned region. We still need to investigate the deformation structure of tensile deformed specimens to know whether <c+a> or prismatic slip was activated or not.