Pulsed Electric Field Based Material Removal in Microelectrical Discharge Machining

Abstract

Micro electrical discharge machining (MEDM), a scaled down version of EDM process, is a micro machining process used to fabricate micro holes and intricate shapes in electrically conductive materials irrespective of its hardness. In this process, an electric spark is generated in the gap between the two electrodes (tool as cathode and workpiece as anode) submerged in dielectric that leads to a plasma formation, which eventually leads to material removal by melting and vaporization. The mechanism of material removal in MEDM is a very complex process and hence has not been understood fully. Simulation of material removal has been carried out in this study by using COMSOL Multiphysics® software to understand the behavior of pulsating electric field in MEDM. Assuming a constant heat flux, it has been shown that material removal takes place whenever the electric field strength at any particular location on the workpiece crosses the threshold value.