Effects of laser energy density on the defects, microstructure and mechanical property of Zn-Mn alloy in selective laser melting

Abstract

The selective laser melting (SLM) was employed to fabricate the biodegradable Zn-Mn alloys, and the density can reach 99.41 %. Mainly focus of the Zn-0.6Mn alloy defects, microstructure and mechanical properties with the laser energy density change rule. The results indicate that extreme laser energy densities give rise to various defects. In contrast, a moderate energy density yields a defect-free and dense surface. The microstructure of the Zn-0.6Mn alloys predominantly consists of fine equiaxed grains and lamellar structures. Compared to pure zinc, the addition of Mn refines the grain size from 24.06 μm to 6.90 μm and enhances the ultimate tensile strength from 81.7 MPa to 208.0 MPa. Additionally, the SLM-fabricated Zn-0.6Mn alloy samples exhibit high ductility (∼17.9 %).