Influence of different process parameters on the mechanical properties of porous structures of 316L stainless steel formed by SLM

ObjectiveTo obtain metal implants with mechanical properties close to those of human bone and to understand the laser melting forming mechanism.MethodsFirst, porous rhombic structures with a designed porosity of 80% were fabricated using stainless steel 316L via selective laser melting. Second, orthogonal tests were conducted with three different values for each of the three process parameters: laser power, scanning speed, and hatch spacing, resulting in 9 samples. Finally, the samples were subjected to annealing at 800 ℃ followed by compression testing.ResultsThe average Vickers hardness is 210.34 HV, the average elastic modulus is 4.84 GPa, the average yield strength is 8.66 MPa, and the average ultimate tensile strength is 440.99 MPa. Laser power has the most significant influence on Vickers hardness, elastic modulus, and yield strength, while hatch spacing has the most significant influence on compressive strength. The results indicate that the mechanical properties of this porous structure are consistent with those of elastoplastic materials, exhibiting high hardness and strength. Its elastic modulus is 97.52% lower than that of dense material, approaching that of human bone. This conclusion provides a reference for research on the mechanical properties of metal implants.