The Preparation And Tribological Properties Of MoS₂-Mo(Ti/N)Composite Coatings

Molybdenum disulfide,as a solid lubricating film has excellent friction and wear performance in vacuum environment,butMoS₂ thin films are easily oxidized and tailed in humid environment,thus limiting its applications in mechanical,electronic,aerospace and other fields.In order to improve the oxidation resistance ofMoS₂ thin films,mainly through co-doped metal or ceramic inMoS₂ thin films at present.Doping Ti inMoS₂ is currently the most widely used,not only improve the oxidation resistance ofMoS₂ thin films in humid environment,but also make the composite thin films has low friction coefficient.The purpose of this study is to find a kind of metal and ceramic dopedMoS₂ thin films not only improve the oxidation resistance ofMoS₂ thin films in high humid air but also has lower friction coefficient thanMoS₂,MoS2-Ti andMoS₂-TiN composite thin films.In this study,MoS2-Mo-Ti,MoS2-Mo2N andMoS₂-MoTiN composite thin films have been deposited by closed field unbalanced magnetron sputtering system.The content of Mo in composite thin films is controlled by varing the currents of Mo targets applied to targets.The results revealMoS₂-Mo-Ti composite thin films,MoS2-Mo2N composite thin films andMoS₂-MoTiN composite thin films as a whole are amorphous,but a big bunch of nanocrystalline has been found inseted into amorphous ofMoS₂-Mo-Ti composite thin films,a small quantity of nanocrystalline has been found inseted into amorphous ofMoS₂-MoTiN composite thin films,There were no nanocrystalline found inMoS₂-Mo2N composite films.The surface roughness ofMoS₂-Mo-Ti composite thin films,MoS2-Mo2N composite thin films andMoS₂-MoTiN composite thin films are lower than pureMoS₂ thin films.In addition,the surfaces roughnessMoS₂-Mo-Ti composite thin films are lower thanMoS₂-T i composite thin films and the surface roughnessMoS₂-MoTiN composite thin films are lower thanMoS₂-TiN composite thin films.With the increasing of the Mo target current,the hardness ofMoS₂-Mo-Ti composite thin films,MoS2-Mo2N composite thin films andMoS₂-MoTiN composite thin films show an ascending trend,which are much higher than pureMoS₂ thin films.In addition,the hardness of as-depositedMoS₂-Mo-Ti composite thin films(8.3?9.8 GPa)are higher thanMoS₂-Mo2N composite thin films(7.8 GPa-9.5 GPa).The adhesion ofMoS₂-Mo-Ti composite thin films when Mo target currents are 0.7 A and 0.9 A,the adhesion ofMoS₂-Mo-Ti composite films when Mo target currents are 0.5 A and 0.9 A and the adhesionMoS₂-MoTiN composite thin films when Mo target currents is 0.9 A,have increased obviously than pureMoS₂ thin films.In the air,the friction coefficient ofMoS₂-Mo2N composite thin films andMoS₂-MoTiN composite thin films,when Mo target currents is 0.3 A,are both lower than pureMoS₂ thin films.In high humid air,MoS2-Mo-Ti composite thin films when Mo target current is 0.5 A,MoS2-Mo2N composite thin films when Mo target current is 0.7 A andMoS₂-MoTiN composite thin films when Mo target currents are 0.5 A and 0.7 A,not only show significantly lower friction coefficient but also show stable friction coefficient.In oil,MoS2-Mo-Ti composite thin films,MoS2-Mo2N composite thin films andMoS₂-MoTiN composite thin films in low load show slightly lower friction coefficient thanMoS₂ thin films.