Abstract This paper investigates the intergranular deformation behavior and its effect on the overall ductility of a Mg-Gd-Y alloy, using in-situ tension in scanning electron microscopy (SEM) combined with electron backscattered diffraction (EBSD) and digital image correlation (DIC) techniques. At regions surrounding grain boundaries, the majority of activated dislocation slip traces were found to form in pairs across grain boundary, and the basal-to-basal (B-B) slip pair is the dominant type. Strain accommodation around the grain boundary interfaces is affected by both Schmid factor in the adjacent grains and the m’ value between these main slip systems. A mk value was proposed in this paper as the maximum value of the product of the Schmid factor and the m’ value of the adjacent grains to measure strain accommodation around the grain boundary interface, where a higher mk value would mean a larger local strain. It is suggested that the overall ductility of a Mg alloy could be evaluated by measuring its average mk value. As an evidence, the Mg-Gd-Y alloy tubes with higher mk value generally show higher elongations during tensile tests in this study.

中文翻译：

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实现镁合金的高延展性——晶间变形的作用

摘要 本文利用扫描电子显微镜 (SEM) 中的原位张力结合电子背散射衍射 (EBSD) 和数字图像相关 (DIC) 研究了晶间变形行为及其对 Mg-Gd-Y 合金整体延展性的影响。 ) 技术。在晶界周围的区域，发现大多数活化位错滑移痕迹在晶界上成对形成，并且基底到基底 (BB) 滑移对是主要类型。晶界界面周围的应变调节受相邻晶粒中的 Schmid 因子和这些主要滑移系统之间的 m' 值的影响。本文提出了一个 mk 值作为 Schmid 因子与相邻晶粒的 m' 值的乘积的最大值，以测量晶界界面周围的应变调节，其中较高的 mk 值意味着较大的局部应变。建议可以通过测量其平均 mk 值来评估镁合金的整体延展性。作为证据，具有较高 mk 值的 Mg-Gd-Y 合金管在本研究中的拉伸试验期间通常显示出较高的伸长率。