Study On Ultrasonic Vibration Assisted Micro Electrochemical Discharge Machining Technology

With the continuous development of micro-electromechanical equipment technology,glass microstructures(hard and brittle non-conductive materials)are widely used in biomedicine,chemistry,aerospace and micro-experimental devices.In this paper,glass is selected as the machining object,and ultrasonic vibration is added to micro-electrochemical discharge machining process.The influence of ultrasonic vibration assistance on the machining principle,process and results of micro-electrochemical discharge machining is discussed.A series of experiments are carried out.The main research work includes:(1)The gas film forming mechanism of electrochemical discharge machining,the influence of ultrasonic vibration on gas film and material removal mechanism are analyzed theoretically;the control model of discharge energy and material removal rate in micro-electrochemical discharge machining drilling and milling is established;the role of ultrasonic vibration in the process of gas film forming is simulated and analyzed.A test platform of ultrasonic vibration assisted micro-electrochemical discharge machining is built.(2)Ultrasonic vibration-assisted micro-electrochemical discharge drilling experiments are carried out.The drilling model is established.The effect of ultrasonic amplitude on the quality of micro-holes machining is investigated.and the optimum ultrasonic amplitude parameter(7.5?m)is obtained.The influence of main machining parameters on machining process and accuracy is analyzed.The results show that the lowest machinable voltage is significantly reduced by adding ultrasonic vibration assistance(voltage drops from 35V to 27V,with a reduction of 22.86%).The machining accuracy is improved(the diameter of micro-hole is reduced from 163.2?m to 135.6?m,with an increase of 16.9%).The stability of the process is improved.Finally,a 3×3 micro-holes array with small hot crack area at the inlet and no damage at the outlet is fabricated.(3)Ultrasonic vibration-assisted micro-electrochemical discharge milling experiments are carried out.Milling model is established.The influence of ultrasonic amplitude on the machining quality of micro-channel is investigated,and the optimum ultrasonic amplitude parameter(7.5?m)is obtained.The influence of main machining parameters on machining process and accuracy is analyzed.The results show that the lowest machinable voltage(voltage drops from 35V to 27V,with a reduction of 22.86%)is significantly reduced by adding ultrasonic vibration assistance.The machining accuracy is improved(the width of the micro-channel is reduced from 138.7?m to 119.2?m,with an increase of 14.1%).The surface roughness of the machined workpiece is reduced(the Ra of the bottom of the micro-channel is reduced from 0.53 ?m to 0.26?m.a 50.94%decrease).Finally,micro-channel array,micro-three-dimensional pentagonal stepped structure and 3 mm diameter simplified micro-channel of Shandong University emblem pattern are fabricated.