Research On Ultrasonic Micro-texture Processing Technology Of Friction Pair Surface

Surface micro-texture is to prepare an array structure with a certain geometric size and arrangement regularity on the surface of a material in a specific way.A large number of studies have shown that the surface micro-texture can effectively reduce the friction and wear of the friction pair,and comprehensively improve the tribological properties of the surface of the friction pair.At present,there are many methods for surface micro-texture processing,but the realization of pollution-free,low-cost and high-efficiency surface micro-texture processing is still the focus and development trend of current research.Therefore,based on the theory of ultrasonic vibration,this paper designs an ultrasonic micro-texture processing device for the surface of the friction pair.The key components are analyzed by finite element analysis and multi-objective optimization design.At the same time,the tribological properties of the surface micro-texture prepared by the device under the oil-lean lubrication state were studied.The specific research content and results are as follows:Based on the ultrasonic vibration theory,the design of the sandwich piezoelectric transducer and the stepped horn is theoretically deduced using traditional analytical methods,then,the material and size parameters are determined.Combining the longitudinal vibration theory and bending vibration theory of the rod,a bending horn that can change the direction of vibration transmission is designed,and the design theory is verified by the finite element method.According to the actual processing requirements,other key components were designed and selected.The modal analysis and harmony response analysis of the main components of the acoustic amplification system were carried out by using ANSYS Workbench,and the structural dynamic characteristics were determined.The results show that there is a certain deviation between the theoretical design results of the main components of the acoustic amplification system and the finite element simulation results,and the structural dynamics of the bending horn is affected by the bending radius.Based on the results of structural dynamics analysis,the main components of the acoustic amplification system were optimized.The influence of various size parameters on the vibration performance of parts is studied through parameter correlation analysis,and the optimal size model of each part is obtained based on multi-objective optimization design.The optimized simulation results are verified by impedance analysis experiment and laser vibration measurement experiment.The results show that the performance indicators of the main components of the acoustic amplification system obtained by the optimized design of this paper have been improved to meet the design goals.Finally,the tribological properties of the surface micro-textures with different densities were studied through friction and wear experiments.The ultrasonic micro-texture processing device designed in this paper was used to prepare surface micro-textures with different densities.The friction and wear test was carried out under the condition of oil-lean lubrication,and the influence of different surface micro-texture density on the friction and wear performance of the friction pair surface under load and frequency stepped loading was studied respectively.The test results show that compared with the untextured samples,the tribological properties of the specimens processed by ultrasonic micro-texturing have been significantly improved,and the specimens with a micro-texture density of 10% show the best wear resistance.