Abstract
To understand the mechanism of material removal in electrical discharge machining, the process of a single discharge must first be understood. In this study, aiming to investigate the influence of bubble behavior on removal volume of the crater, we observed bubble behavior during single discharge using a high-speed video camera. In experiment, a low-melting-temperature alloy expected to allow the generation of large craters was used to conduct detailed observations of individual single craters. A thin tungsten electrode was used, and the current was fixed at 20 A. To investigate whether change in bubble behavior is related to removal, double-pulse discharge experiments were conducted. And the influence of the expansion direction of a bubble was modified by using a jig that limited the height of the bubble. In addition, laser irradiation in pure water was conducted under conditions of limited bubble height. On these results, we conclude that the expansion and shrinkage directions of the bubble are important factors that affect the removal volume in EDM.
