Thermal oxidation of Zr-2.5Nb alloy and its biotribological properties

Zirconium alloys are potential materials for permanent implants due to their suitable mechanical strength, good biocompatibility, and superior corrosion resistance. However, Zr-2.5Nb alloys are greatly limited to the applications of artificial joints due to their poor tribological properties. Thermal oxidation is considered as a good way to improve the tribological properties of Zr-2.5Nb alloys. The effect of temperature on the properties of thermal oxidized Zr-2.5Nb alloys was investigated to understand the growth mechanism of ZrO2 coating. In addition, the surface hardness of the thermal oxidized Zr-2.5Nb alloys was examined. Finally, the tribological properties of the thermal oxidized Zr-2.5Nb alloys were investigated to evaluate the potential application in artificial hip joints. The results showed that ZrO2 coating was successfully synthesized on the surface of Zr-2.5Nb alloys, and the temperature has significantly effects on the thickness of the ZrO2 coatings. It also found that thermal oxidation could significantly improve the surface hardness and wear resistance of Zr-2.5Nb alloys.