Feasibility of 3-D Surface Machining by Dry EDM

摘要

To study the feasibility of 3-dimensional surface machining by dry EDM, a dry EDM machine that can blow gas from a rotating pipe electrode was prototyped. Of factors thought to affect dry EDM performance, cut depth, gas pressure, pulse duration, pulse interval, and revolution of tool electrode were taken up as machining parameters to investigate their influence on machining performance. The results revealed optimum combinations of cut depth and gas pressure for realizing maximum work removal rate as well as minimum tool electrode wear ratio. It was also found that there exist optimum combinations of pulse duration and pulse interval for EDM pulse. Based on these results, micro shaped samples were machined by dry EDM. Compared to oil EDM, tool electrode wear ratio was about 1/3 smaller, and the profile accuracy was excellent. However, because not much improvement was seen for the work removal rate, methods for further enhancing work removal rate must be reviewed for realizing a practical application.