Experimental study on horizontal ultrasonic electrical discharge machining

Electrical discharge machining (EDM) is usually used to machine conductive difficult-to-machine materials by pulse discharge, which can achieve high processing quality, but the machining efficiency is low. Ultrasonic vibration of the electrode changes the discharge gap and enhances the chip removal ability, which is deemed as an excellent method to increase the EDM efficiency. In this paper, firstly, a new ultrasonic vibration unit is designed with the assistance of finite element method (FEM) simulation for the resonance oscillation of the workpiece on the end of the amplitude transformer in horizontal direction. Secondly, the machining parameters, including the gap voltage, pulse interval, pulse width and peak current in the traditional EDM process, are optimized by experiments, and the optimized condition is applied to the horizontal ultrasonic electrical discharge machining (HU-EDM) process. In comparison with the traditional EDM, HU-EDM increases the material removal rate (MRR) by nearly 3 times, and improves the processing accuracy by 20%. Through this research, it is confirmed that both advantages of machining accuracy and machining efficiency are achieved in HU-EDM.