Analysis of Discharge Current in Wire-EDM Considering Electromagnetic Fields in and between Electrodes

摘要

In wire electrical discharge machining (WEDM), discharge current is one of the important factors which determine the machining properties, such as machining speed or machining accuracy. Previously developed machining simulators of WEDM, however, neglected the influence of workpiece conditions on the discharge current. Hence, this study developed a simulation tool for analyzing the discharge current in WEDM, where the electromagnetic field analysis around the wire electrode was coupled with the analysis of the equivalent circuit of the entire pulse generator circuit. The simulation results showed that, under the same pulse voltage and duration, the discharge current may change depending on the electromotive force which is determined by material properties, geometry and size of workpiece and wire electrode. In this study, the discharge current was calculated with different workpiece thicknesses. In addition, the discharge current was measured and compared with the calculation results in order to show the validity of the simulation tool.