Research On Solid Lubrication Mechanism Of Graphene By H13 Laser Micro Texturing

The two objects which contact with each other have friction when the relative motion occurs,there are three key points of correct understanding of tribology: friction,wear and lubrication.It is an effective measure to prolong the service life of the machine,improve the work efficiency and reduce the unnecessary economic loss by reducing the friction and wear and improving the lubrication state.Surface texture with solid lubrication technology came into being,because of surface texture has been paid attention to by many scholars as a kind of bionics technology and solid lubrication shows good lubrication effect compared with liquid lubrication.In this paper,the friction behavior and mechanism of H13 surface texture with solid lubrication were systematically studied by means of finite element simulation,process technology and friction test.The corresponding conclusions are as follows:Firstly,on the basis of establishing the two-dimensional cross-section model of ring-ring contact,and the control variable method was used to analyze the mechanism of solid lubrication and the influence of texture parameters（diameter,depth and density）on the stress.The results show that the existence of texture changes the stress distribution between the contact surfaces and alleviates the stress concentration between the contact surfaces,then the orthogonal design is designed to optimize the texture parameters.The results show that the influence of texture parameters on stress from small to large are diameter,density,depth,respectively,and the diameter is 140μm,the density is 23% and the depth is 14μm are the optimal combination of texture parameters.Secondly,the surface texture processing of H13 samples was studied by K20-CS fiber laser marking machine.The results show that the geometrical parameters of the surface texture（diameter and depth）increase with the increase of the output power of the marking machine.With the increase of the number of marking,the texture depth increases almost linearly,but the diameter increases with the increase of the number of marking,then increases and then decreases.With the increase of laser scanning speed,the diameter of micro texture showed a trend of increase,and the depth is increased with the increase of laser scanning speed decreases,and 500mm/s scanning speed is the turning point of significant changes inthe diameter and the depth of the micro texture.The microstructure of the laser has some influence on the surface hardness of the specimen,and the hardness in the micro-texture is increased by 56.82%.The filling process of solid lubricant was discussed and characterized by "cold bonding method".The results show that the solid lubricant has a good filling effect,the method to calculate the filling rate of a single texture is about 96.35%,the overall surface microstructure of the filling rate of about 83.33%.Finally,the friction test was carried out by MWW-1A microcomputer controlled universal friction and wear tester.The results show that under the current experimental condition,the change trend of increasing quality of the average friction coefficient of MoS₂ composite with solid lubricant in the ratio and decreases first and then increases,and when the mass ratio is 40%,the lubricating effect of composite solid lubricant is the best.The average friction coefficient of four kinds of textures is from small to large: ring,arc,linear and square.Compared with other samples,the lubricating condition of the texture solid lubricating sample is the best,the friction coefficient and the wear are the smallest,and the variation range of the friction coefficient is less affected by the change of the speed and the load.