MoS2/a-C复合薄膜在高/低湿度环境下的摩擦学性能研究

采用磁控溅射方法制备了MoS_2薄膜与不同碳含量的MoS_2/a-C复合薄膜,利用XRD、SEM、Raman光谱仪、纳米压痕仪和CSM摩擦试验机等分析了复合薄膜的结构、力学和摩擦学性能.结果表明:MoS_2薄膜为疏松的柱状结构,MoS_2/a-C复合薄膜为无定形的致密结构,硬度较高.低湿环境下MoS_2薄膜与MoS_2/a-C复合薄膜的摩擦性能差别不明显;高湿环境下薄膜的摩擦系数和磨损率均有所升高,其中MoS_2薄膜与低碳含量的MoS_2/a-C复合薄膜氧化严重,而高碳含量的MoS_2/a-C复合薄膜的摩擦学性能稳定,对湿度交替变换的环境适应性更佳.这是由于碳元素掺杂改善复合薄膜的微观结构,提高复合薄膜的抗氧化性和力学性能.

Tribological Properties of MoS2/a-C Composite Films under High/Low Humidity Environments

In this study, the MoS₂ film and MoS₂/a-C films with two C contents were deposited by unbalanced magnetron sputtering. The structure, mechanical and tribological properties were investigated by X-ray diffraction, scanning electron microscopy, nanoindentor and CSM tribometer. The results show that MoS₂ film presented loose columnar structure with well crystalline state, while the MoS₂/a-C composite films appeared amorphous state with much dense microstructure. Moreover, the MoS₂/a-C composite films possessed relatively higher hardness compared to the MoS₂ film. The friction coefficient and wear rate of the films were all found to be very low, and there were no obviously variations with the change of C content under low humidity (RH 15%). However, under high humidity (RH 75%), the friction coefficient of the MoS₂ film and the MoS₂/a-C composite film with low C content was relatively high and unstable with rather high wear rate as the serious oxidization. The MoS₂/a-C composite film with high C content exhibited relatively lower and stable friction coefficient, as well as relatively lower wear rate compared to the MoS₂ film and the MoS₂/a-C composite film with low C content. The film also provided stable performance and recovery of low friction in multiple humidity cycles. The excellent properties of the MoS₂/a-C composite film were attributed to the relatively denser microstructure, high hardness and excellent oxidation resistance properties.