偏压及测试环境对新型MoS2-Ti复合膜摩擦学性能的影响

采用新型高功率脉冲复合磁控溅射技术制备MoS2-Ti复合膜,并研究基体偏压和测试环境对复合膜摩擦学性能的影响.结果表明:制备的MoS2-Ti复合膜表面呈现颗粒状结构,Ti在薄膜表层与O反应形成氧化物有效抑制MoS2的氧化.随着基体负偏压从OV增大到-400 V,复合膜的S/Mo原子比逐渐减小.在-300 V偏压下,颗粒堆积最为紧密,薄膜硬度和弹性模量达到最大值,分别为9.7和137.1GPa,并具有最低的平均摩擦系数值(0.04)和磨损率(10-7mm3/(N·m)].多种测试环境下的摩擦研究显示:在室温大气环境下复合膜的摩擦学性能与其结构的致密性紧密相关,而在N2以及不同湿度环境下薄膜表现出的优异摩擦学性能则归因于在摩擦过程中有效形成的转移膜贡献.

Effect of Bias and Test Environments on Tribological Behavior of MoS2-Ti Composite Coatings

The MoS₂-Ti composite coatings were deposited by a new hybrid high power impulse magnetron sputtering. The effect of the substrate bias and the multiple test environments on the tribological performance of the coatings was discussed. The results show that the composite coatings presented the granular surface morphology. The presence of titanium oxides from reaction of Ti with oxygen on the surface inhibited the oxidation of MoS₂. The atomic ratio of S to Mo decreased with the increase of the substrate negative bias from 0 V to -400 V. The hardness and elastic modulus reached the maximum value at the substrate bias of -300 V, due to the much denser microstructure with the smooth surface. Meanwhile, the composite coatings exhibited the lowest average friction coefficient (0.04) as well as the wear rate 10^-7 mm³/(N·m)]. The tribological behaviors under multiple test environments indicate that the microstructure densification of composite coatings played a key role in the lubrication performance in ambient environment, while the excellent tribological property in N₂ and various humidity conditions was greatly attributed to the effective formation of transfer film during friction tests.