Electrical discharge machining with isolated bundled fine wire electrodes

This paper deals with the phenomenon in which two little electrical discharge craters are generated when one impulse discharge is added to two close thin insulated electrodes. Based on the experimental results, a new electrical discharge machining method is proposed with isolated bundled fine wire electrodes. In this method, the surface roughness is not deteriorated even if high discharge energy is added to an electrode in order to obtain the high removal rate. The influences of the discharge current on the discharge crater shape were investigated by using the bundled electrode of fine insulated wire. Furthermore, the effects of the repetitive discharge on the surface roughness were experimentally investigated. As a result it was found that the generated crater on the workpiece consisted of plural craters when the peak current was over 200A, and many shallow and wide craters were generated when the peak current was over 400A. The experimental analysis made it clear that the proposed method was effective for high performance electrical discharge machining.