Low Friction Properties of Si-Incorporated DLC Coatings Treated with Oxygen Plasma

本研究通过控制Si-DLC涂层中氧化硅的用量，研究氧化硅层对Si-DLC涂层摩擦性能的影响。采用氧等离子体处理30 ~ 300 s，控制Si-DLC涂层上氧化硅的含量。结果表明，随着氧等离子体处理时间的延长，Si-DLC涂层顶表面氧化硅含量增加。3-7at硅- dlc涂层的摩擦系数。经氧等离子体处理后，%Si降至0.02，低于含13at.%Si的Si- dlc涂层。氧等离子体处理后Si-DLC涂层的表面硬度略有下降，主要是由于表面形成了氧化硅，而磨损轨迹的硬度与氧等离子体处理前Si-DLC涂层的硬度基本相同。在Si-DLC涂层上形成的富硅氧化层起到刻蚀层的作用，降低摩擦系数。氧等离子体处理在不降低整体Si-DLC涂层硬度的情况下，能有效降低摩擦系数。

In this study, the effects of silicon oxide layer on frictional properties of Si-DLC coatings were investigated by controlling the amount of silicon oxide on Si-DLC coatings. The amount of silicon oxide on the Si-DLC coating was controlled by oxygen plasma treatment for 30-300 s. In a result, the amount of silicon oxide on the top surface of Si-DLC coating increases with the increasing treatment time of oxygen plasma. The friction coefficients of Si-DLC coatings with 3-7at.%Si decrease to 0.02 due to oxygen plasma treatment, which is the lower value than that of Si-DLC coating with 13at.%Si. The surface hardness of Si-DLC coatings is slightly reduced by oxygen plasma treatment due to formation of silicon oxide on the top surface, whereas the hardness of wear track exhibits the same value to Si-DLC coating before oxygen plasma treatment. The Si-rich oxide layer formed on the Si-DLC coating plays roll of scarifying layer to reduce friction coefficient. The oxygen plasma treatment is effective to reduce the friction coefficient without hardness reduction in the entire Si-DLC coating.