Research On The Effect Of Cavitation On The Surface Formation Of Ultrasonic Edm

Difficult-to-machine materials are more and more widely used in various fields,but due to the special physical properties of materials,they are difficult to process and manufacture.Ultrasonic vibration-assisted EDM technology has a good machining effect on difficult-tomachine materials,which has attracted extensive attention of researchers.In order to further explore the shock wave and high temperature and high pressure environment formed by the collapse of cavitation bubbles caused by ultrasonic waves acting on the fluid.In this paper,the collapse of cavitation bubbles,the effect of shock wave on the workpiece surface and the change of workpiece surface quality are gradually analyzed from theory,simulation and experiment.The main research contents are as follows:Firstly,the related theory of cavitation effect and the model of cavitation bubble are simplified.Based on the dynamic equation,energy equation and shock wave equation of cavitation bubble,the corresponding numerical solution is obtained by using MATLAB.The influence of three main factors,ultrasonic frequency and sound pressure amplitude,on cavitation effect and cavitation shock wave intensity.Secondly,in the pre-processing of HYPERMESH,the material settings of the cavitation bubble,the workpiece and the liquid coating area are set,and then LSDYNA is used as the simulation software to carry out the correlation analysis,and finally the results of the relevant simulation calculation are obtained in the post-processing of HYPERMESH.Simulates the change of a single cavitation bubble from the initial state to the collapse process and its influence on the workpiece,the pressure change on the workpiece and the speed change on the left and right sides of the cavitation bubble itself,as well as for different initial radii and different The pressure change produced by the initial velocity on the surface of the workpiece,using the finite element method,it is confirmed that the cavitation effect can improve the surface quality of EDM.Finally,the percentage of total power provided by different ultrasonic power sources is studied through experiments.By analyzing the surface morphology of the machined workpiece and measuring the surface roughness of the machined workpiece,it is compared with the theoretical calculation results.The surface quality of EDM workpieces with cavitation effect is better than that of ordinary EDM.After adding ultrasonic,the surface roughness value of the workpiece is reduced by about 9.3%-27.9%,while the ultrasonic cavitation effect reduces the surface roughness value of the workpiece about up 17.0%.