The failure mechanism of molybdenum disulfide thin-film lubrication under the reciprocating motion of space rolling bearings remains unclear.This study proposed a method to analyze the thin-film lubrication process using molecular dynamics.A friction atomic model of the single-layer molybdenum disulfide film was established.The reciprocating oscillation simulation of the molybdenum disulfide film was carried out based on two important factors affecting space rolling bearing:load and ambient temperature,focusing on friction,adhesion,and wear.Simulation results reveal that friction of the Fe-Ni-Cr alloy probe on the single-layer molybdenum disulfide film exhibits stick-slip motion.The probe's friction within the range of 20～100 nN does not induce wear on the film;however,it enhances the film's lubrication performance during reciprocating motion.Starting from 200 nN,the probe's friction process causes wear on the film,leading to a continuous increase in friction coefficient during reciprocating motion and a decrease in lubricating performance.The load limit for a single-layer film is found to be 400 nN,beyond which the probe pierces the film and contacts the substrate,resulting in rapid wear and loss of lubrication effect.Ambient temperature below 1 773.15 K has no significant effect on the film's lubrication effect.However,above this temperature,the film boundary starts to melt slowly.Upon reaching the melting point of molybdenum disulfide,the film's melting speed accelerates,leading to a loss of lubricating effect.Conclusions drawn from the study are as follows:The contact load of the molybdenum disulfide monolayer film exhibits excellent wear resistance and lubricity below 8 GPa;in the event of film damage,repeated friction processes can improve lubricating performance;the two-dimensional layered structure significantly influences the lubricating properties of the monolayer molybdenum disulfide film,and exposure to high temperature and heavy load can damage the film's layered structure.
关键词
二硫化钼/Fe-Ni-Cr合金/分子动力学仿真/微观摩擦/空间滚动轴承
Key words
molybdenum disulfide/Fe-Ni-Cr alloy/molecular dynamics simulation/microscopic friction/space rolling bearings
维普
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