Study of the effect of SLM energy density on residual stress and microstructure of porous bone scaffolds in cubic structures

Abstract

In order to investigate the effect of energy density in selective laser melting (SLM) forming on the properties of porous bone scaffolds made of 316L stainless steel, the mechanism of different construction energy densities on the residual stress and microstructure of cubic porous bone scaffolds was investigated by combining experiments and finite element analysis. The results showed that many defects were formed in the scaffolds when too high or too low energy densities were used to form the porous bone scaffolds. In terms of microstructure, inappropriate energy densities caused some grains to appear coarse and dispersed, which directly led to a reduction in the corrosion resistance of the scaffolds. Most importantly, the stress and temperature field changes in the melt pool during the SLM forming process were obtained through finite element calculations and analysis, and it was found that the residual stress in the scaffolds was proportional to the energy density. After a comprehensive study of the finite element analysis results and experimental characterization, the optimum energy density for constructing cubic porous bone scaffolds with ideal defects and residual stress in the porous bone scaffolds was obtained.

Keywords

• porous bone scaffolds
• selected laser melting
• residual stress
• microstructure
• finite element analysis