ABSTRACT
Electrical discharge machining (EDM) is a thermal process that uses spark discharges to erode electrically conductive materials. The EDM machine is one of the most commonly used pieces of nontraditional equipment in industry. Regardless of their complexity, all EDM systems comprise four major subassemblies that include the power supply, dielectric system, electrode, and servosystem. The power supply transforms the alternating current (AC) from the main utility electrical supply into the pulsed direct current (DC) required to produce the spark discharges at the machining gap. Many materials have been successfully used for EDM applications. The common requirements for candidate materials are that they be readily available, easily machinable, exhibit low wear, be electrically conductive, and provide good surface finishes on the workpiece. Parameters are manually selected on most EDM systems, although some systems use CNC units or programmable controllers to adjust and match parameters for various applications.
