An index to evaluate the wear resistance of the electrode in micro-EDM

The EDM is very complex including plasma formation in the dielectric, interaction between electrons and thermal ions, and heat transfer. It has been known that the mechanism of material removal in EDM is based on electrical energy transfer and thermal process. However, energy transfer from electric energy into thermal energy is still an unknown topic, particularly in micro-EDM using small energy (<100 μJ). In this study, the effects of thermal properties on electrode wear were investigated. It was evident that the boiling point of the electrode material plays an important role in the wear mechanism of micro-EDM. Therefore, the boiling point cannot be negligible in considering the wear resistance of the electrode material. A proposal is to introduce a new function where the latent heats are taken into account as a modified type of the temperatures. The experimental data obtained in micro-EDM performance shows strong correlation with this new index.