Thermal oxidation of Ti6Al4V alloy and its biotribological properties under serum lubrication

• Rutile TiO2 film was formed on titanium alloy after thermal oxidation.
• The nanohardness of TiO2 film was 21.11 GPa.
• TiO2 film exhibited low friction coefficient and high wear resistance.
• Thermal oxidized titanium alloy was a potential candidate for artificial joints.

The purpose of this work was to develop a thermal oxidation technique to improve the wear resistance of titanium alloy for the application of biomedical field. It was found that rutile TiO2 film was formed on the surface of titanium alloy after thermal oxidation at 700 °C in a gas mixture of nitrogen with 40% oxygen by volume ratio. The nanohardness of TiO2 film was 21.11 GPa, 299.1% higher than that of titanium alloy. The biotribological test revealed that thermal oxidized titanium alloy exhibited low friction coefficient and high wear resistance, which indicated that the thermal oxidized titanium alloy could be a potential candidate for artificial joints.