Research On Friction And Lubrication Characteristics Of PDMS Friction Pairs With Textured Surface

With the development of surface texture technology,it has become more and more mature in friction reduction,friction enhancement,vibration reduction,anti-adhesion and other technologies.By processing a series of microstructures on the surface of an object according to certain rules and shapes,the friction and wear characteristics of the object can be changed to a certain extent.However,at present,the research on surface texture is mostly focused on rigid materials,while for flexible materials,such as PDMS,the friction and lubrication characteristics of the surface microstructures of friction pairs of polymer materials are relatively scarce.Flexible materials are more and more widely used in the field of mechanical industry.Therefore,it should be an important direction of surface texture theory research to explore the influence of surface texture of flexible materials on fluid lubrication and the improvement of friction characteristics,and then optimize the surface texture of flexible materials to obtain excellent friction and lubrication characteristics.In this paper,the mathematical models of different surface texture morphologies of flexible material PDMS are established.Combining with Reynolds equation,the numerical simulation is carried out by using five-point difference method with MATLAB software.The friction and lubrication characteristics of different surface textures under the change of the moving speed of friction pairs and lubrication conditions are studied.By combining Reynolds equation with elastic deformation expression of materials,the law of friction and lubrication characteristics of PDMS materials with textured surfaces under different moving speed of friction pairs and lubrication conditions was analyzed.In the experimental part,the friction characteristics of PDMS specimens with different surface textures at different rotating speeds and different pairs were experimented by using MMW-1 universal friction and wear tester.The results show that:(1)By comparing the surface texture friction pairs with the surface non-texture friction pairs with different morphologies,it is found that the friction coefficient of the surface non-texture friction pairs is significantly higher than that of the friction pairs with different surface textures.It is shown that adding surface texture with certain morphology can reduce friction and improve friction and lubrication characteristics to a certain extent,and cylindrical texture can better reduce friction and improve friction and lubrication characteristics than other surface textures.(2)By changing the moving speed of the friction pair and the lubricant viscosity,it is found that the friction coefficient on the surface of the friction pair increases with the increase of the moving speed of the friction pair or the increase of the lubricant viscosity,and the friction coefficient increases linearly with the change of the speed and the viscosity.(3)Through theoretical calculation,it is found that the surface elasticity of the non-textured area is much higher than that of the textured area under the condition of the change of velocity and viscosity.It shows that the elastic deformation of PDMS material surface will directly lead to the increase of friction coefficient of friction pairs,thus affecting the friction and lubrication characteristics.(4)The experimental results show that the friction coefficients of PDMS-PDMS pairs and PDMS-structural steel pairs increase with the increase of rotational speed.Compared with non-texture,micro-trench texture and micro-trench texture show good friction reduction characteristics,and micro-trench texture has the best friction reduction characteristics.The friction coefficient of PDMS-structural steel pair is smaller than that of PDMS-PDMS pair,which indicates that the friction reduction characteristic of PDMS-structural steel pair is better.Figure [46] table [13] reference [51]...