Abstract
This paper investigates the machining phenomena in electrical discharge machining (EDM) of carbon fiber reinforced plastics (CFRP) in order to understand its machining process. Sinking EDM using deionized water for machining liquid and wire EDM were carried out, and machining properties, such as material removal rate and electrode wear ratio, were compared with those of EDM of metal. The waveforms of discharge current and gap voltage were also observed during the machining process, and the ratio of the short-circuiting was evaluated. Experimental results show that Sinking EDM and wire EDM of CFRP can be realized without using special machining method and equipment. It is found for the sinking EDM of CFRP that electrode wear ratio decreases with increasing the discharge current, and the ratio less than 1% can be achieved even when deionized water is used for the machining liquid. It is also found that the short-circuiting caused by the contact of carbon fibers that are fluffing on the machined surface with the tool electrode frequently occurs, and the short-circuiting contributes to material removal.
