Electrical discharge machining in distilled water

Abstract

The performances of kerosene and distilled water as the dielectric fluid in electrical discharge machining (EDM) were compared over the pulse energy range 0.72 – 288 mJ. Machining in distilled water resulted in a higher metal removal rate and a lower wear ratio than in kerosene when a high pulse energy range (72 – 288 mJ) was used. With distilled water, the machining accuracy was poor but the surface finish was better. Electron microprobe analysis revealed that the deposition of tool material (copper) on the work surface (high carbon steel) was low when machining took place in distilled water at a high pulse energy (288 mJ) and in kerosene at a low pulse energy (72 mJ). It is concluded that distilled water may be used as a dielectric fluid in EDM at a high pulse energy range.