Effect of remelting strategy on forming mechanism of selective laser melted AlSi10Mg

Abstract

Selective laser melting (SLM) technology is widely used in various fields for manufacturing high-precision and complex parts. However, SLMed parts still exhibit some microstructural defects. The remelting strategy provides a new approach for defect elimination in SLM process, named as selective laser remelting (SLRM). In this study, the effects of remelting strategy on the melt pool were revealed through a finite element model. The porosity, microstructure, surface roughness, microhardness and tensile behavior of the specimens were also evaluated. The links between the formation mechanism of the melt pool and various experimental results were explored. The simulation results showed that the SLRMed melt pool had a significantly lower temperature and a shorter liquid phase time. The experimental results demonstrated that the remelting strategy effectively reduced the porosity, improved the density of the specimens, and provided a finer microstructure. The remelting strategy effectively reduced the surface roughness of the top surface of the specimens, while slightly adversely affecting the surface roughness of the side surface. Additionally, the microhardness and tensile properties of the specimens increased correspondingly due to the finer microstructure formed inside the SLRMed melt pool. These findings contribute to a better understanding and application of the remelting strategy for producing high-quality parts.