Machining Characteristics of EDM by Radio-frequency Plasma

An extension to the electrical discharge machining method by introduction of radio-frequency plasma is proposed. Sparking with the radio-frequency plasma can be generated in paraffin oil by simple electrical circuitry. In this paper, experimental investigations are described on the fundamental effects of the resonant frequency, type of electrode and workpiece materials on machining characteristics for high performance radio-frequency machining in paraffin oil. The results show that the removal rate and the electrode wear vary with the resonant frequency and type of electrode materials. The surface roughness can be reduced to less than 1μm Rz under suitable experimental conditions.