Functions of Working Fluid in Electrical Discharge Machining

Abstract

This paper describes some functions of working fluid in electrical discharge machining (EDM). EDM oil is usually used in die-sinking EDM, whereas deionized water is usually used in wire EDM. First, the effect of working fluid on material removal is explained. Heat flux and pressurizing at the discharge spot, prevention of reattaching of removed molten metal on machining surface and prevention of tool electrode wear are affected by the working fluid. Then, the effect of working fluid on stability of machining process is explained. Extension of gap width, cooling of tool electrode and workpiece and exclusion of debris from gap space are important functions of the working fluid.