Parameter optimization and microhardness experiment of AlSi10Mg alloy prepared by selective laser melting

AlSi10Mg alloy processed by selective laser melting (SLM) has a high potential for the aerospace and auto industry. However, the process parameters induced density and microstructure will have a significant impact on material properties. The samples density, hardness, microstructure, and grain morphology were measured by the Archimedes drainage method, hardness tester, microscope, and SEM. This work has found that the density of the AlSi10Mg sample is directly proportional to the Vickers hardness. The optimum density (2.676 g cm−3) and Vickers hardness (115.92 HV) are obtained in the range of laser energy density (LED) of 48-63 J mm−3. The microhardness variation trend of the X-Z cross-section molten pool in the horizontal direction fluctuates greatly. The closer the vertical direction is to the lower boundary of the molten pool, the lower the microhardness value, which is due to the difference in microhardness caused by the microstructures. Therefore, high density and fine microstructure are of great significance to improve material performance.