Study On Micro Texture And Friction Properties Of Ultrasonic Elliptical Vibration Assisted Cutting Surface

Friction and wear has always been an important reason for parts failure and energy waste.Improving friction performance can effectively improve the reliability and service life of mechanical system,and reduce energy consumption.It is proved that the surface micro texture technology can effectively reduce the friction and wear of the surface of the parts,and the reasonable micro texture parameters can make the friction performance best.In this paper,based on ultrasonic elliptical vibration assisted cutting,the friction properties of the micro-texture of the cylindrical surface are studied,and experimental analysis is carried out around the micro-texture processing parameters,shape size,and lubrication mechanism.Firstly,the surface micro-texture model including the cutting speed,feed speed,cutting depth,the overall contour of the tip,the main-deflection angle,the frequency and the amplitude of the ultrasonic vibration was established based on the ultrasonic elliptical vibration-assisted cutting mechanism.The accuracy of the model was verified through experiments.The influence of the machining factors on the circumferential length,the axial length and the arrangement position of the micro texture is analyzed by the micro texture model,and a specific algorithm is given.According to the working principle of the sliding bearing,a friction test device was designed,and the friction experiment was carried out.The friction coefficient and surface wear condition of smooth surface specimens,ordinary cutting specimens and micro-texture specimens with the same cutting parameters were experimentally studied.The results show that the micro-texture can effectively reduce the friction coefficient of the parts during the lubrication operation.With the increase of friction speed,the anti-friction effect of micro-texture is significantly enhanced.Observing the surface condition of the specimen,it was found that the surface of the micro-texture specimen was not substantially worn,and there was a slight scratch on the surface of the smooth specimen,while the surface of the ordinary specimen showed the most serious wear,which means that the micro texture can effectively reduce the wear of the friction pair surface.The research on the anti-friction mechanism of the micro-texture surface shows that the lubrication mechanism when the micro-texture surface slides under ultrasonic cutting is the result of many factors,including: increasing the surface wetting performance,secondary dynamic pressure lubrication,increased surface hardness,and storage of abrasive particles reduce wear.In the study of micro-texture processing parameters,it is found that the increase of cutting speed will reduce the friction coefficient of micro-texture,and as the cutting speed increases,the reduction of friction coefficient will gradually decrease;The friction coefficient will rise with the increase of feed speed,the greater the feed rate,the greater the increase in the coefficient of friction.In the study of the micro-texture shape and size,it was found that the shape of the micro-texture has an important influence on the friction properties.With the reduction of the ratio of the long axis to the short axis of the micro texture,the friction coefficient decreases.When the micro-texture morphology is close to a circle,the micro-texture surface has the lowest friction coefficient,and the friction performance reached the best.