Micro-electrical Discharge Milling Operation

Abstract

This chapter introduces a novel variant of electric discharge machining (EDM) process entitled to electrical discharge milling (ED-Milling) operation. Although the mechanism of material removal is essentially identical to that of conventional EDM process, the intricacies arise predominantly pertaining to the multiple zones involved simultaneously during the sparking phenomenon. Unlike the Ram/die-sinking EDM or ED-Drilling operations comprising merely unidirectional control of the tool electrode, the ED-Milling operation is characterized by the synchronized movement of the tool in multiple axes (generally x-, y-, and z-axis) besides the high-speed rotation about its axis. This controlled motion of the tool electrode governed by the programmed instructions similar to the computerized numerical control (CNC) of conventional milling operation makes it a prospective contender especially for fabrication of 3D micro/macro-profiles. Incorporating a comparatively simpler cylindrical or in exceptional instances rectangular/square cross-sectional tool electrode to generate a complex three-dimensional feature is the distinctive capability of this operation. The chapter comprises the basic introduction to EDM process in conjunction with ED-Milling operation, different techniques of micro-tool production as well as micro-fabrication, suitability of ED-Milling operation for a variety of sophisticated areas, analysis of tool wear and the possible applications areas of the process.