Generation of bio-compatible titanium alloy surfaces by laser-induced wet treatment

A laser-induced surface treatment in wet conditions was developed for improving the biocompatibility of titanium alloys. Disk-shaped titanium samples were soaked in a calcium nitrate solution and subsequently irradiated by a Yb fiber pulse laser beam, creating a modified surface layer containing calcium and oxygen elements. The modified layer exhibited optimal properties for treatment at a defocus distance of -1 mm and for a calcium nitrate concentration of 10%. The apatite-forming ability of the modified surface was affirmed in bioactivity tests performed in the simulated body fluid. It was shown that a Ca-rich layer was stably generated by the modified treatment process. The generated Ca-rich layer demonstrated superior biocompatibility, suggesting increased hydroxyapatite content. (C) 2016 CIRP.