This study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

这项研究调查了等通道角挤压（ECAP）结合热处理对通过选择性激光熔化（SLM）和重力铸造制备的AlSi10Mg合金的组织和力学性能的影响。特别关注的是确定制造后热处理对使用两种不同方法制造的AlSi10Mg合金的组织演变的影响。在ECAP变形之前考虑了三个初始合金条件：（1）在固溶处理（T4）条件下铸态；（2）在T4条件下的SLM；（3）经过低温退火的SLM。使用光学显微镜，透射电子显微镜，X射线衍射线加宽分析和电子反向散射衍射分析来表征ECAP之前和之后的微观结构。结果表明，相对于其他两个条件，SLM随后进行低温退火导致了优异的机械性能。显微分析表明，部分细胞结构有助于强大的加工硬化。这种行为增强了材料的强度，因为在ECAP变形过程中增加了几何上必要的位错的积累。