ELID Grinding and EDM for Finish Machining

Abstract

Electrolytic in-process dressing (ELID) grinding and electro-discharge machining (EDM) are among major nontraditional machining processes used in manufacturing industries. ELID grinding uses metal-bonded super-abrasive wheel with in-process electrolytic dressing for grinding hard and brittle materials. The fine abrasive wheels in ELID grinding is able to achieve ductile machining of the work material. Continuous protrusion of sharp grits is maintained by electrolytic dressing of the grinding wheel in-process with a pulsed DC power supply. The combined effect of ductile machining and sharp grit ensures nanometric surface finish on hard and brittle materials by ELID grinding. EDM, on the other hand is used on conductive materials to achieve nanometric surface. A pulsed DC or RC-based DC power supply is used between the tool and workpiece in EDM process in presence of dielectric fluid. As the tool approaches near to the workpiece, the dielectric breakdown occurs and a spark is generated, which creates a crater on the workpiece. A controllable and repeated spark erodes the workpiece and replicates the tool shape on the workpiece. This chapter includes study of ELID grinding and EDM operations as finish machining methods with comprehensive discussions on different aspects of ELID grinding and EDM operations.