超声液相剥离制备二维MoS_(2)作为润滑脂添加剂的摩擦学研究

Tribological study on preparation of two-dimensional MoS_(2) as grease additive by ultrasonic liquid phase stripping

通过超声液相剥离法制备不同片径的二硫化钼纳米片,并将其作为添加剂应用到锂基润滑脂。通过电子显微镜、拉曼光谱、X射线衍射仪和热重分析仪对所制二硫化钼纳米片的形貌、组成和结构进行表征;利用四球摩擦磨损试验机考察二硫化钼锂基润滑脂摩擦学性能,通过扫描电子显微镜和X射线光电子能谱分析MoS_(2)润滑脂润滑下钢球的磨损表面形貌,初步探究MoS_(2)的润滑机理。结果表明:二硫化钼纳米片表现出优异的抗磨减摩性能,当添加片径为80 nm,添加量为1.0%(质量分数)时,锂基润滑脂摩擦学性能最佳,最大无卡咬负荷和烧结负荷相较于基础脂分别提升了55.4%和61.2%,摩擦因数最高减小了23.15%,磨斑直径最高减小了21.13%。其摩擦学性能的提高主要与形成了Fe的各类氧化物、FeOOH、MoS_(2)和相关有机物构成的摩擦保护膜有关。

MoS_(2) nanosheets with different sizes were prepared by ultrasonic liquid phase stripping and used as additives in lithium grease.The morphology,composition and structure of MoS_(2) nanosheets were characterized by electron microscopy,Raman spectroscopy,X-ray diffractometer and thermogravimetric analyzer;the tribological properties of lithium MoS_(2) grease were investigated by using four-ball friction and wear testing machine.The wear surface morphology of steel ball under MoS_(2) grease lubrication was analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy,and the lubrication mechanism of MoS_(2) grease was preliminarily explored.The results show that MoS_(2) nanosheets show excellent wear resistance and friction reduction performance.When the diameter of the added sheet is 80 nm and the amount is 1.0%(mass fraction),the tribological performance of lithium grease is the best,the maximum no-bite load and sintering load are increased by 55.4%and 61.2%respectively compared with the base grease,and the friction coefficient is decreased by 23.15%.The maximum diameter of wear scar diameter is decreased by 21.13%.The improvement of its tribological properties is mainly related to the tribological protective film composed of various oxides of Fe,FeOOH,MoS_(2) and related organic matter.