为研究基材冷却状态对激光沉积成形AlSi10Mg合金质量和性能的影响,在不同冷却条件下沉积成形AlSi10Mg合金试样。利用温度测量系统、金相显微镜、扫描电镜、万能材料试验机对成形过程中温度演变和成形后试样宏观形貌、组织状态、拉伸性能等进行分析。结果表明:合理的基体冷却温度会使沉积效率提升,缺陷率降低;改变冷却条件可以使沉积层组织发生显著变化,内部的枝晶间距明显减小。优化冷却条件后沉积试样的屈服强度和抗拉强度较无冷却条件下的分别提升了约4%和7%,其断裂方式均为韧性断裂。

In this study, the laser deposited AlSi10Mg alloys are formed under different cooling conditions to investigate the effect of the substrate cooling condition on the deposition qualities and properties. Further, we analyze the temperature variation during the forming process, morphologies, microstructures, and tensile properties of the formed specimens using the temperature testing systems, an optical microscope, a scanning electron microscope, and a universal material testing machine, respectively. The results denote that the deposition efficiency increases and the defect rate decreases when a reasonable substrate cooling temperature is considered. The deposition layer structure can be significantly altered when the cooling conditions are changed. In addition, the dendrite space of the deposition specimen is observed to decrease. The tensile strength and yield strength of the specimens fabricated under the cooling condition are improved by approximately 4% and 7%, respectively, when compared with those of the specimens fabricated without applying any cooling conditions. Furthermore, the fracture mode of the specimens is ductile fracture.