Study On The Tribological Behavior Of MoS₂ Self-Lubricating Coatings Prepared By CVD Method

Solid lubricants can significantly reduce the friction coefficient,reduce wear,and enhance load bearing capacity of the workpiece.As typical solid lubricating material,MoS2 has unique layered structure and low friction coefficient,which is widely used in aerospace fields.However,MoS2 coating prepared by traditional method exhibited complex technology,high cost and difficult to coat the surface of complex workpiece,resulting in limited widespread application.Chemical vapor deposition(CVD)is widely used to prepare anti-moisture-wear coatings due to simple process structure.The coating possess strong adhesion and good adaptability to the environment.In this paper,MoS2/Sb/Ag self-lubricating coatings were prepared by CVD deposition technology.The effects of vapor deposition parameters on the structure and properties of the coatings were studied.Tribological behavior of composite coatings in different environments(atmospheric environment,deionized water,sea water,lubricating oil)and different loaded were analyzed.The wear mechanism,friction coefficient and wear resistance time of the coating were analyzed.Relevant research results provide theoretical and experimental support for the preparation of MoS2 composite coatings with high adaptability in multi-friction environment in mechanical processing,tool abrasives and engines field.The distance between the substrate and Mo source have significant effects on the structural composition and tribological properties of the lubrication coatings.The coating exhibited compact structure and excellent mechanical and tribological properties with proper distance.When the distance is 5 cm,lubrication coating has compact structure,smooth and gray-bright surface,less intermediate products and high tribological properties.Metal Sb and Ag elements can be evenly doped into the coatings by vapor deposition.As hard particles,metal particles can effectively improve the interlayer adhesion of MoS2 coatings and the tribological properties of the composite coatings.The friction environment has significant impact on the tribological behaviors of MoS2/Sb/Ag.The dense structure and strength bond interlayers effectively supress corrosion of oxygen and water vapor into film.Then the friction coefficient of the coatings lower than that of pure MoS2 coatings,and prolongs life is 12%times that of pure MoS2 coatings,in the atmosphere with 80%relative humidity.In the water environment,the wear is aggravated and the life is decreases of coating;in the brine environment,because of the aggravation of the corrosion by brine the wear life of the coatings is decreases sharply;in the condition of lubricating oil,the excellent tribological properties of the composite coatings are attributed to the self-lubricating coatings and lubricating oils.Under different load conditions,the initial friction coefficient decreases with the increase of load;the long-term friction coating is peeled by contact stress,which results in the failure of lubrication,and this phenomenon is aggravated with the increase of load.