Abstract:To further increase the binding force between titanium substrate and carbon film and enhance the protective properties of the coatings, a titanium oxide coating structure with metallurgical bonding for the substrate has been prepared using a ion beam deposition technique micro-arc oxidation (MAO) technique, and then a carbon film was deposited using ion beam deposition combined magnetron sputtering technique on this titanium oxide coating to obtain the duplex coating. Microstructure and properties of the coatings were comparatively studied by SEM+EDS, AFM, wear test and electrochemical experiment. Results showed that the surface carbon film could not completely cover the micropores of the MAO coating, and the MAO titanium oxide coating on Ti substrate had porous features, which effectively increased the binding force between the top carbon film and the Ti substrate. The Ti substrate/MAO coating/carbon film system had the lowest friction coefficient, smallest fluctuation and width of wear scar in the process of friction, showing the most excellent tribological performance. However, the corrosion resistance of the new design composite coating was worse than the Ti substrate/Ti interlayer/carbon film. This was related to a thin carbon film and porous characteristics of MAO coating of the composite coating, resulting in the corrosion medium easily into the interface between the carbon film and MAO coating through the micropores and reducing the resistance corrosion.