Effect of Surface Treatment on Surface Characteristics and Biocompatibility of AISI 316L Stainless Steel

Surface characteristics are essential in determining the biocompatibility of medical implants. Surface treatments such as mechanical polishing, electropolishing, passivation and plastic strain of AISI 316L stainless steel was found to affect the critical surface tension, with the combined electropolishing and passivation treatment resulting in the most desirable critical surface tension for biocompatibility. AES and XPS analysis showed that electropolishing results in changing the surface chemical composition significantly. There is significant Cr enrichment on the surface, compared to the bulk. The surface Cr and Fe exist as a combination of oxides and hydroxides.