Effect of Aging Treatment on Mechanical Properties of AlSi10Mg Alloy Fabricated by Selective Laser Melting

AlSi10Mg alloy was prepared by selective laser melting technology, and the direct aging treatments were conducted to investigate the effect of aging treatment on its comprehensive mechanical properties. The results indicate that after direct aging treatment, the relative density of the alloy is more than 99.41%, which is basically unchanged. The hardness of the alloy initially decreases and then increases with the increase of direct aging temperature, and reaches its maximum value (125.68 HV) at 180 ℃. With the increase of direct aging temperature, the fracture failure mode of the alloy transitions from ductile-brittle mixed fracture to brittle fracture, and its tensile strength, yield strength and elongation all exhibit a trend of first increasing and then decreasing. When the aging temperature is 120 ℃, the alloy exhibits the most significant work hardening effect, and the initial strain hardening rate reaches 0.835 GPa. During the high strain stage, the strain hardening rate decreases slowly. The alloy exhibits the best comprehensive mechanical properties at this aging temperature, when the tensile strength, yield strength and elongation reach 461.48 MPa, 434.86 MPa and 18.11%, respectively.