Study On The Dry Friction Characteristics Of Surface Microstructure Of The Steel Ball Expanding Surface

Steel ball nondestructive testing is an important part of ensuring the quality,spherical expansion of the steel ball surface quality testing equipment depends on the core part named expansion wheel.The excessive wear of the expansion wheel can cause the deviation of the steel ball movement,the detection accuracy and efficiency will be reduced.At present,each test 50 thousand balls need to replace the expansion wheel,but the expansion wheel is expensive and is completely depended on importation.Therefore,it becomes an urgent problem to improve the wear resistance of the expansion wheel.We apply the technology of microstructure to expansion wheel.There is a need for further research on microstructure of friction characteristics.In this paper,aiming at the wear problem of expansion wheel,microstructure is designed with different geometric parameters,based on the characterization of microstructure for physical properties through microhardness test,for analyzing the characteristics of the microstructure and wear behavior.According to the actual work condition of expanding wheel to design experimental scheme,combining the surface properties of microstructure to analyze friction behavior and wear characteristics,determine the shape parameters of microstructure for optimal friction properties.Based on Archard wear theory and the analysis of experiment,considering the effect of modified materials caused by micro processing on wear properties,the paper put forward a wear model for microstructure.Numerical simulation of wear process is finished by ANSYS wear subroutine,simulation and experimental results with an average error of 5%,the validity of wear model for microstructure and the feasibility of the numerical simulation model are verified,to further improve the wear theory of surface microstructure.Finally,aiming at the square and diamond pit microstructure selected by experiment,according to the wear model for microstructure established by the paper,in the area of variable for numerical simulation,determine the best area of dimple microstructure for wear resistance.This paper has completed the expansion wheel surface microstructure of wear-resisting design,prolonged the service life of the unwinding wheel,and provided a new idea and method for study of wear properties of microstructure.