In the study, the through-thickness microstructure and its effects on the ductility and strain heterogeneity in high-pressure die-cast AE44 alloy were investigated. The results show that the studied alloy had a gradient microstructure, where two fine-grained skins sandwiched a core with coarse externally solidified crystals (ESCs) embedded in fine grains. In the core, where porosity concentrated, the ultra-coarse ESCs with sizes up to 600 μm were observed. A great amount of Al₁₁RE₃ phase, as the predominant intermetallic phase, was distributed in homogeneously through the thickness. High-resolution digital image correlation (DIC) measurement coupled with electron backscatter diffraction (EBSD) was employed to reveal the deformation inhomogeneity and its root cause. It was found that considerable strain localization mainly appeared in the ultra-coarse ESCs with soft orientation for basal slip and the regions where porosity appeared. Unlike the yield strengths and ultimate tensile strengths, the elongations showed a significant variation. Not only defects but also the ultra-coarse ESCs were the primary factors responsible for the variation in ductility.

在研究中，研究了高压压铸AE44合金的贯穿厚度组织及其对延性和应变异质性的影响。结果表明，所研究的合金具有梯度微观结构，其中两个细晶粒的表层将芯夹在中间，而粗大的外部凝固晶体（ESC）嵌入细晶粒中。在核心，其中孔隙率浓缩，用尺寸超粗的ESC高达600 μ m的观察。大量的Al ₁₁ RE ₃相作为主要的金属间相，均匀地分布在整个厚度上。高分辨率数字图像相关性（DIC）测量与电子背散射衍射（EBSD）结合使用，揭示了变形不均匀性及其根本原因。结果发现，相当大的应变局部化主要出现在基体滑动方向软，孔隙度大的超粗电调中。与屈服强度和极限拉伸强度不同，伸长率显示出显着的变化。不仅缺陷，而且超粗电调也是造成延性变化的主要因素。