Surface Modification of Graphite by Electrical Discharge Machine

Electrical Discharge Machining (EDM) is a widespread technique used in industry for high-precision machining of all types of electrical conductive materials. Though it is generally a material removal process, migration of tool material onto the workpiece surface had been observed during machining by EDM and hence this phenomenon has been exploited by many researchers for surface modification. Further, deliberate material transfer has been carried out under specific conditions by using selected tool material onto the machined surface for obtaining specific functional characteristics. In this aspect, Powder Metallurgical (P/M) electrode plays a significant role. In this present work, an attempt for surface modification of graphite using P/M tool electrode of W/Cu, Cr/Cu, Ni/Cu, Si/Cu and Si/Graphite/Cu has been made to obtain a uniformly deposited layer over the graphite base material. Parametric analysis of the performance measures viz. Material Transfer Rate (MTR), Tool Wear Rate (TWR) and surface roughness (Ra) has been done by varying the input parameters. The investigated input process parameters are composition, pulsed on-time/off time and peak current.