Research On Ultrasonic Vibration And Magnetic Field Complex Assisted EDM Blind Hole Machining

With the continuous exploration,electrical discharge machining(EDM)has been widely used in its rich processing forms,including cutting,profiling,punching and other application forms.These different forms of processing can solve problem of chipping removal and meet the needs of processing diversity.For larger blind hole machining,the internal flushing EDM can not be achieved.EDM machines can not effectively and effectively eliminate the influence of machining chips in the processing area when processing blind holes,and there is a problem of concentrated discharge.Therefore,the ultrasound and magnetic fields are simultaneously introduced into the machining process to improve the negative effects of these two aspects.This paper first analyzed the effect of the intense motion of the liquid in the processing domain caused by ultrasound on the elimination of unfavorable factors,including the breaking action of large bubbles in the blind hole gap and the circulation of the medium liquid generated by the reciprocating piston movement.The theoretical study of the state of the inter-electrode plasma after the addition of the magnetic field and the ultrasonic wave is the surface precision model to obtain that the deflected diffusion plasma will produce a better surface condition.Then,the electric field distribution of the tool surface of different diameters was simulated and the blind hole processing tests of different diameters were carried out.The test was analyzed by multiple evaluation criteria.The simulation results show that the discharge energy is mainly concentrated on the outer surface of the discharge end,and the change of the potential is related to the set pulse time and the size of the processing blind hole.At the same time,according to the results of blind hole test with different sizes,it was found that thedifference of the same machining condition is caused by change of electric potential of difference discharge surface.The differences of surface morphology of the same machined caused by the difference in potential distribution between different parts of the same machining surface are determined by different electric potential distribution between different parts of the same discharge surface and the discharge state of machining dbris of.Finally,the longitudinal vibration test piece and the transducer test device were designed,and the type of magnetic circuit and the magnetic source material were selected according to the size of the obtained test piece,and a magnetic field device was designed.a comprehensive comparison test of the amplitude factors of the ultrasonic wave was carried out.The ultrasonic amplitude parameters in the ultrasound and magnetic field complex assisted processing were optimized,and four kinds of different processing methods of different currents and different voltages were compared with eachmplitud factors.The test shows that the influence of the ultrasonic amplitude change on the processing effect is very weak.The processing efficiency and surface precision obtained by the ultrasonic magnetic field composite assisted processing method are better than the single assist method in a certain parameter range,but the dimension accuracy of the blind hole is worse than that of ultrasound-assisted.Ultrasound-assisted methods are poor.Ultrasonic-assisted EDM machining method improves machining efficiency by 60% under small current,and reduces machining efficiency under large current,while magnetic field-assisted EDM machining method has better processing effect under larger current.At the same time,the two-objective optimization analysis of the ultrasonic magnetic field composite EDM blind hole was carried out by means of mean optimization.