Effects of Process Parameters on the Microstructure and Properties of Selective Laser Melting 316L Negative Re-entrant Hexagonal Honeycomb Porous Bone Scaffolds

The 316L porous bone scaffolds prepared by selective laser melting (SLM) are now widely used in bone defects. The successful implantation of porous bone scaffolds is based on the premise that they have compatible properties with human bone, and the process parameters used in the shaping of the porous bone scaffolds significantly affect their properties. In this study, we investigated the effects of process parameters on the performance of SLM 316L porous scaffolds based on the structure of negative re-entrant hexagonal honeycomb (NRHH) through a combination of finite element analysis and experimental methods using MSC Simufact Additive forming process simulation and SLM forming experiments. The effect of process parameters on the performance of SLM 316L NRHH porous scaffolds was explored. The results show that the selection of process parameters significantly affects the magnitude of residual stress, defect distribution, microstructure, and properties of scaffolds. The residual stress in the scaffolds increased and the grain size decreased and then increased as the energy density increased. The grain size and defect distribution determine the mechanical and corrosion resistance of the scaffolds, and the smallest grain size (230 nm) and optimum corrosion resistance are obtained at the energy density E = 58.33 J/mm³.