Research On Anti-friction Property Of Textured Surface Of Bearing Steel Processed By Femtosecond Laser

In mechanical equipment,friction and wear generally reduce the stability and reliability of the system,which will result in a reduction in the life of a mechanical system and waste of resources.Therefore,it is significant to reduce the friction and wear phenomenon of friction pairs.The method,which is to improve friction properties of friction pairs through textured surface,has attracted many international scholars,and it has become the focus of current tribology research.In these paper,three aspect was discussed,which included the theory and simulation of textured surface lubrication,the process of textured surface by femtosecond laser and the tribological properties of textured surfaces.Firstly,a dynamic lubrication model of a single texture was established,based on N-S equation and fluid lubrication theory.The simulation showed that different parameter of texture had important influence on the surface lubrication;The relationship between the dynamic pressure and the depth ratio was analyzed;The effects of different shapes and cross sections on dynamic pressure lubric ation were compared.All above was for the follow-up test to provide the appropriate theoretical support.Secondly,the processing technology of GCr15 bearing steel by femtosecond laser was studied.The ablation threshold of bearing steel GC15 material w as calculated with the result of the experiment.On this basis,the influence of different pulse energy and pulse number on the shape of the pits was analyzed,The relationship between the pit depth and the pulse energy and the number of pulses was fitted,which provided the basis for the process control of this material.The effects of laser repetition rate,laser scanning speed and repetition frequency on trench processin g were analyzed,the study showed that only the appropriate scanning speed and laser frequency could achieve high quality trench processing.Finally,the micro-texture of the array processing technology was studied to do a little improvement,Proposed a combination of scanning methods and single-point processing to improve processing efficiency.Finally,The friction performance of different micro-textured surfaces was tested by reciprocating friction test and rotating friction test.The results show ed that the circular micro textured surface had good antifriction performance at different s peeds and loads,while the friction coefficient of the triangular microstructure surface was different in different sliding directions.The microstructure surface had the best surface density,and the friction coefficient was the smallest.The result of simulation was verified by pit test with different depth to diameter ratio.The textured surface had better wear resistance.