Research On The Optimization Of 40cr Groove Surface Texture And Its Friction Characteristics And Mechanism

In recent years,surface texture,as a surface modification method which can effectively improve the tribological properties of friction pairs,has gradually become one of the most potential research directions at home and abroad.In this paper,laser surface texture technology is used to process groove texture and mesh texture,and these texture morphologies are researched to optimize the laser surface texture processing technology.Based on the experimental and finite element methods,the effect of morphology parameters on the dry friction properties of the two kind of textured surfaces is studied,and the influencing mechanism of various factors on the friction properties of the friction pair is deeply analyzed.The main research contents are as follows:On the basis of the principle of pulse laser processing,the optimization experiment of laser surface texture processing is carried out.Through the experimental data analysis and morphology observation,the influence of laser output power,defocus,scanning times,scanning speed and pulse frequency on the morphology of surface groove texture and processing quality of material surface is studied.The optimized laser processing parameters under this experimental condition are determined,which lay a foundation for the research on the tribological properties of the subsequent textured friction pair.Based on the optimized laser surface texturing process parameters,two kinds of surface textures are processed on the 40 Cr substrate.For two kinds of morphological texture surfaces,friction and wear experiments are used as the main research methods to study the effects of surface texture shape,area ratio,motion orientation and other parameters on the friction coefficient and wear amount of the friction pair.It is found that there is a better ratio of surface area and angle of movement for the surface of the line-groove type texture,which can effectively reduce the friction coefficient of the friction pair and the wear amount of the texture surface under dry friction conditions.For the mesh texture,the changes of surface area and the angle of motion cause the changes of tribological properties of friction pairs,but they can not play the role of friction reduction and abrasion resistance.The grinding balls wear amount of the both types of textured friction pairs is higher than that of the non-texture friction pairs.On the basis of the experiment,the wear spots of texture surfaces and the dual parts are analyzed with the aid of three-dimensional morphology observation instrument and electron microscope,and the formation mechanism of the textured friction pair and the non-texture friction pair is analyzed.The contact process of friction pairs is simulated by finite element method,and the distribution of stress on the surface of the specimen is studied.The influence mechanism of various factors on the tribological properties of the friction pair is deeply studied by the analysis of the wear spots and the finite element simulation,which provides a theoretical basis for the design and optimization of the surface texture.