钛表面微弧氧化+碳膜的制备与表征

Preparation and characterization of micro-arc oxidation and carbon film on Titanium

摘要:

为提升钛金属与碳膜的界面结合,增强涂层的防护作用,利用微弧氧化(MAO)技术在钛表面快速简易制备出与基体为冶金结合的多孔层结构,并以此为基采用离子束复合磁控溅射技术制备碳膜。采用SEM+EDS、AFM分析所制备膜层的微观结构,借助划痕仪、磨损试验机和电化学工作站表征膜层的结合力和性能。结果表明：表层碳膜并不能完全覆盖微弧氧化层的微孔,同时Ti基体表面微弧氧化层可有效增加表层碳膜与Ti基体的结合力；Ti基体/MAO层/碳膜的膜基体系在摩擦磨损过程中,摩擦系数小且波动很小,磨痕宽度最小,表现出最为优异的摩擦学性能；而新设计复合膜层的耐蚀性较传统的Ti基体/Ti打底层/碳膜的膜基体系要差,这与表层碳膜较薄,复合膜层仍呈现出微弧氧化层多孔特征有关,其导致腐蚀介质易于通过微孔而降低耐蚀性。

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.