Material removal mechanism in low-energy micro-EDM process

Extensive experiments have been carried out to understand the fundamentals in micro-EDM and especially the material removal mechanism in the finishing regimes of micro-EDM with a RC type generator. Oscillation of the sparking current and voltage has been observed when a high open-voltage was applied and this phenomenon has been predicted by electrical simulations and further experimentally verified. Experiments show that the effect of negative current flow in the sparking gap is not a simple polarity switch. Contrary to the conventional understanding, the negative current flow in a single sparking cycle is also contributing to effective material removal on the workpiece.