Investigation Of Microstructure And Properties Of Molybdenum Disulfide Based Composite Films Deposited By Magnetron Sputtering

In order to improve friction and wear properties of MoS₂ films in humid air at room temperature, MoS₂-Ti-WS₂, MoS₂-Ti-C and MoS₂-TiN composite films were prepared by magnetron sputtering. For comparison, pure MoS₂ and MoS₂-Ti films were deposited under the same conditions. The composition, microstructure and morphology of the films were analysed by X-ray diffraction, energy dispersive X-ray spectroscopy and scanning electron microscope. The adhesion to substrate, nanoindentation hardness and friction coefficient of the films were tested by nanoindenter and UMT-2 multi-functional tribometer tester, respectively. In addition, worn surfaces of films were characterized. The friction and wear properties were investigated in humid air at room temperature.The microstructure and properties of MoS₂-Ti-WS₂ composite films, which were prepared by magnetron co-sputtering at a working pressure of 0.3 Pa, were investigated. It has been observed that, no (100) diffraction peaks appear for both MoS₂-Ti and MoS₂-Ti-WS₂ films, which exhibit granular structure, agglomerated nanosized grains and are more compact than pure MoS₂ film; while pure MoS₂ film has typical porous and worm-like surface structure. Compared with pure MoS₂ and MoS₂-Ti films, the MoS₂-Ti-WS₂ composite films have higher nanoindentation hardness, longer steady-state friction time, lower friction coefficient and smaller fluctuation range. The worn surfaces show MoS₂-Ti-WS₂ composite film has smaller depth and width. The wear rate value for MoS₂-Ti-WS₂ composite film is much lower, which means it has much better wear resistance.MoS₂-Ti-C and MoS₂-TiN composite films were deposited by reactive magnetron sputtering at a working pressure of 1 Pa. The study of microstructure and properties shows that, pure MoS₂ film has preferred orientation of (100) plane and columnar plate morphology with inherent porosity, called type I film. MoS₂-Ti film has mixture of (002) and (100) crystal orientation with loose construction. MoS₂-Ti-C and MoS₂-TiN composite films have strong basal orientation of (002) crystal plane and compact microstructure, called type II films. The adhesion to substrate and nanoindentation hardness were improved significantly for the composite films. Pure MoS₂ and MoS₂-Ti films are shown to have larger fluctuation and higher friction coefficient, that is, about 0.35 and 0.22, respectively; while it is steady, about 0.1 for the MoS₂-Ti-C and MoS₂-TiN films. The wear rate values for MoS₂-Ti-C and MoS₂-TiN composite films are much lower than those of pure MoS₂ and MoS₂-Ti films, which shows that MoS₂-Ti-C and MoS₂-TiN composite films have much superior friction reducing and anti-wear properties.