Molybdenum disulfide/carbon multilayer films achieve ultra-low wear in vacuum

Although diamond-like carbon (DLC) films are known for their low friction and wear properties in atmospheric environments, they commonly experience failure in vacuum environments. On the other hand, MoS2 exhibits a low friction coefficient under vacuum conditions, but its columnar structure limits its load-bearing capacity and results in high wear rates. In this study, we prepared MoS2/DLC multilayer films using a high-power impulse magnetron sputtering (HIPIMS) technique and examined the composition, bonding structure, mechanical properties, and frictional wear of the resulting films. The study findings revealed that the multilayer film exhibits a significantly low coefficient of friction (0.04), particularly in vacuum conditions (5 x 10(-3) Pa). Remarkably, compared to the pure MoS2 film, the wear rate of the multilayer film is reduced by two orders of magnitude, wear rate as low as 3.6 x 10(-9) mm(3)/Nm. Additionally, the DLC component enhances the hardness and reduces the wear rate of the multilayer film. Furthermore, the use of nanometer thickness (17 nm) allows for the incorporation of more MoS2 and DLC layers, which promotes the formation of graphene bands and further reduces the friction coefficient and wear rate. Our findings open new avenues for the application of MoS2 and DLC in vacuum environments.