Study on decreasing tool wear in EDM due to arc spots sliding on electrodes

This paper describes a novel method to reduce tool electrode wear in electrical discharge machining (EDM) by applying the relative sliding motion between electrodes. Experimentally, it was found that the cathode spot is more likely to slide on the electrode surface than the anode spot. Heat conduction analysis showed that material removal increases once with the moving speed of the heat source when the moving speed is low. After peaking at the maximum value, the material removal starts to drop, resulting in almost no material removal with the ultimate speed. In this study, the end of a tungsten anode rod was therefore machined by a copper cathode disc rotating at a high circumferential speed. The results showed that tool electrode wear ratio decreases with increasing rotational speed.