MoS_2-Al复合薄膜高温摩擦学性能研究

Tribological Properties of MoS_2-Al Composite Films at High Temperature

目的提升MoS_2薄膜在高温环境下的润滑性能。方法应用非平衡磁控溅射技术共溅射MoS_2靶和Al靶沉积MoS_2-Al复合薄膜。通过场发射扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)、纳米压入仪和CSM牌高温摩擦磨损试验机,评价MoS_2-Al复合薄膜表面及断面形貌、微观结构、机械性能和高温环境下的摩擦学性能,并通过奥斯巴林显微镜观察磨痕及磨斑形貌。结果温度超过400℃时,Al含量(原子数分数)为18.3%的MoS_2-Al复合薄膜表现出了优异的高温润滑性能,摩擦初始阶段的摩擦系数保持在0.07左右,平均摩擦系数低至0.172,比纯MoS_2薄膜的摩擦系数降低了64%,摩擦曲线十分稳定。结论当薄膜中Al的添加量为18.3%时,Al的引入在不破坏MoS_2结构时起到了自身优先氧化的作用,从而保护了MoS_2结构不被破坏,使MoS_2-Al复合薄膜在高温环境下的润滑能力得到了显著提升。

The work aims to enhance lubrication properties of MoS2 films in high temperature environment. Co-sputtering MoS2 and Al targets were used to deposit MoS2-Al composite films by adopting unbalanced magnetron sputtering. Surface, sectional morphology, microstructure, mechanical property and tribological property in high temperature environment of the MoS2-Al composite films was evaluated with field emission scanning electron microscope （SEM）, X-ray diffractometer （XRD）, X-ray photoelectron spectroscopy （XPS）, nano indenter and CSM high temperature friction and wear tester, respectively. Morphology of grinding cracks and spots was observed with Olympus microscope. When the temperature exceeded 400 ℃, the MoS2-Al composite films with Al content of 18.3 at.% exhibited excellent lubrication property at high temperature, friction coefficient maintained at nearly 0.07, and average friction coefficient was 0.172, which decreased by 64% compared with that of pure MoS2 films. Friction curve of the composite films was steady. The optimum amount of Al in the film is 18.3%, the addition of Al has the effect of preferential oxidation while preserving the MoS2 structure, thus protecting the MoS2 structure from being destroyed, and significantly enhancing lubrication capacity of MoS2-Al composite films in high temperature environment.