Study on the effect of dynamic chemical polishing treatment on porous titanium alloy scaffolds fabricated using laser powder bed fusion

This study addresses the issue of a significant amount of unmelted powder adhering to the surface of Laser Powder Bed Fusion (LPBF) porous titanium alloy scaffolds, and the current inability of existing technologies to effectively handle such surface defects. Porous titanium alloy scaffolds with a triple periodical minimal surface (TPMS) Gyroid structure were prepared using powder bed fusion technology for dynamic chemical polishing. The spatial and surface morphology, as well as the mechanical properties of the scaffolds, were evaluated before and after treatment. Concurrently, fluid finite element simulation was employed to analyze the flow state of the solution inside the porous scaffold during dynamic chemical polishing. Cell culture samples were prepared and subjected to dynamic chemical polishing to study the specific effects of scaffold surface morphology on cell activity. The results indicate that the surface treatment effect, internal and external homogeneity, and dynamic and static mechanical properties of the porous scaffolds with a Gyroid structure are significantly improved after dynamic chemical polishing. Additionally, it was found that dynamic chemical polishing could effectively reduce the micrometer roughness and increase the nanometer roughness of the sample surface, thereby enhancing the adhesion, proliferation, and differentiation activities of Human Bone Mesenchymal Stem cells.