Influence of Nano-zirconia on Micro-arc Oxidation Film of TC4 Titanium Alloy

With the multifunctional micro-arc oxidation power source, the micro-arc oxidation was conducted on TC4 titanium alloy through the treatment with the mature and widely-used electrical parameters. Nano-zirconia of different concentrations was added into the electrolyte to investigate the variation of microstructure and comprehensive mechanical properties of the micro-arc oxidation film. The influence of nano-zirconia on the film was discussed. Results show that with increasing the nano-zirconia concentration, the film thickness barely changes, but the composition and component concentration of the film differ: the brookite phase appears in the film, and its concentration is increasing. When the nano-zirconia concentration is 2 g/L, the roughness of the film layer is greatly reduced, compared with that without nano-zirconia addition, and the wear resistance of the film layer is optimal. In addition, the micropore diameter on the layer surface is the smallest and uniform, and the corrosion resistance is optimal.