Post-fabrication heat treatment, including solution treatment (at 520 °C for 1 h) followed by water quenching (WQ), air cooling (AC) and furnace cooling (FC), was performed on a selective laser melted AlSi10Mg alloy. The objective is to assess the effect of various cooling rates on the microstructure (specifically eutectic-Si morphology) and small-scale mechanical properties, measured by employing a depth-sensing nanoindentation platform, of the selective laser melted AlSi10Mg alloy. Results show extensive evolutions in the microstructure and the mechanical properties of the heat-treated materials relative to the as-fabricated sample. Upon solutionizing treatment, the eutectic Si is first fragmented, then spheroidized, and finally coarsened when cooled with slow rates. The microstructural evolution directly affects the mechanical properties, where the as-fabricated and the FC are the hardest and the softest structures, respectively. This is directly attributed to the size and morphology of the eutectic-Si within the microstructure. The findings of this study could help to adjust the optimized heat-treatment process to fabricate SLM AlSi10Mg parts with desirable microstructure and mechanical properties.

在选择性激光熔化的AlSi10Mg合金上进行了后加工热处理，包括固溶处理（在520°C下进行1小时），然后进行水淬（WQ），空冷（AC）和炉冷（FC）。目的是评估各种冷却速率对选择性激光熔化的AlSi10Mg合金的微观结构（特别是共晶Si形态）和小规模机械性能（通过采用深度感应纳米压痕平台测量）的影响。结果表明，相对于加工后的样品，热处理材料的微观结构和机械性能发生了巨大变化。固溶处理后，共晶硅首先破碎，然后球化，最后以慢速冷却时粗大。微观结构的演变直接影响机械性能，加工后的和FC分别是最硬和最软的结构。这直接归因于微结构内共晶硅的尺寸和形态。这项研究的发现可以帮助调整优化的热处理工艺，以制造具有理想的组织和机械性能的SLM AlSi10Mg零件。