The microstructure and mechanical properties of TiN and TiO2/TiN duplex films synthesized by plasma immersion ion implantation and deposition on artificial heart valve

Improving the blood compatibility of titanium alloy artificial heart valves by TiO2/TiN duplex films was studied. In the duplex TiO2/TiN film, the titanium oxide is for improving blood compatibility and the TiN film is mainly to improve the mechanical property of the films. The mechanical properties of TiN films synthesized by plasma immersion ion implantation and deposition at different bias voltages and substrate temperatures are studied. Its structure is examined using X-ray diffractometry and TEM. The fatigue property of the artificial heart valve modified by TiO2/TiN duplex film is also investigated. The fatigue property and the wear resistance of the artificial heart valve modified by TiO2/TiN duplex film are significantly improved compared with bare titanium alloy artificial heart valve. The present investigation shows that TiO2/TiN duplex film is suitable for applications such as artificial heart valve coating.