The improvement of wettability, biotribological behavior and corrosion resistance of titanium alloy pretreated by thermal oxidation

• A thickness of 7 μm rutile TiO2 coating formed by a new thermal oxidation process.
• UHMWPE pin with a spherical crown was adopted under 25% bovine serum lubrication.
• Friction coefficients and wear volumes of treated sample all decreased by about 50%.
• Wettability and corrosion resistance of treated sample were significantly improved.
• Protein in bovine serum played an important role in biotribological and corrosion test.

The thermal oxidation process was performed on biomedical titanium alloys to improve surface properties for the application in artificial cervical disc. The pretreated Ti6Al4V was characterized with XPS, XRD and SEM. The wettability, biotribological behavior and corrosion resistance were evaluated under distilled water and 25 wt% bovine serum lubricant. Rutile TiO2 as the main compound was formed with the increase in hardness. The wettability was improved significantly after oxidation. Compared with the untreated, the friction coefficients and wear volumes of treated samples all decreased with about 50% reduction in both dry sliding and lubrication conditions. Corrosion resistance for oxidized samples was also enhanced with a big reduction of corrosion current density and a shift in corrosion potential towards the positive direction.