Performance of EC-PCD Made of Boron Doped Diamond as an Electrode for EDM of Cemented Carbide

Electrically conductive PCD (EC-PCD), which was made of electrically conductive diamond particles, was applied to an electrode for EDM. In this study, properties of EC-PCD electrode in the EDM of cemented carbide were investigated and the results were compared with those of copper-tungsten (Cu-W) electrode and standard PCD (S-PCD) electrode. In terms of EDM speed, 35μm/min with Cu-W electrode, 15μm/min with S-PCD electrode and 22μm/min with EC-PCD were recorded. As for the electrode wear rate, though Cu-W electrode wore by 20-30%, S-PCD and EC-PCD did not wear at all and even the electrode length became longer by several micro meters. Roughness value of the EDMed surface was Rz=8μm with both Cu-W and S-PCD, while it was Rz=3μm in the case of EC-PCD. From the above, it was found that EC-PCD showed excellent performance in the electrode wear rate and the roughness of the EDMed surface, though EDM speed was 0.7 times of Cu-W electrode.