Cavity-Type Electrical Discharge Machining

Cavity-type electrical discharge machining (EDM) is a thermal mass-reducing process that uses a shaped conductive tool to remove electrically conductive material.  It does this by means of rapid, controlled, repetitive spark discharges.  A dielectric fluid is used to flush the removed particles, to regulate the discharge, and to keep the tool and workpiece cool.

Process Characteristics

Advances a shaped tool to within sparking (arcing) distance of the workpiece
Tools and workpieces must be electrically conductive
Removes material by rapid, controlled, repetitive spark discharge
Uses a dielectric fluid to flush removed particles, control discharge, and cool tool and workpiece
Surface finish is affected by gap voltage, discharge current, and frequency

Back

Information provided is from Manufacturing Processes Reference Guide by Robert H. Todd, Dell K. Allen, and Leo Alting.--1st ed. Published by Industrial Press Inc., 1994.