Microstructure and mechanical properties of CNC-SLM hybrid manufacturing 316L parts

Abstract

In this study, 316L stainless steel powder was deposited on the machined (CNC) 316 L stainless steel using selective laser melting (SLM) technology. The block-shaped hybrid manufacturing samples that combine machining (CNC) and SLM process were prepared. The microstructure and microhardness of the substrate region, SLM region, and interface region were analyzed by different mechanical property characterization and microstructural techniques. The horizontal and vertical hybrid manufacturing tensile patterns were prepared, and the tensile properties of the hybrid manufacturing samples were measured by the tensile test. The results show that the SLM part is relatively dense, and there is no crack at the connection between the substrate and the SLM region. The grains at the interface joint are refined, and the tensile fracture of the hybrid manufacturing part in the vertical direction appears on the substrate region, indicating that the strength of the joint is higher than the strength of the substrate. The yield strength and tensile strength of the horizontal hybrid manufacturing tensile parts reached 497.5Mpa and 607.5 Mpa, and the elongation rate was 45.23%, showing good mechanical properties. This kind of hybrid manufacturing improves the production efficiency of SLM direct production parts and reduces the cost, which has a wide range of application prospects.