Modelling and optimisation of material removal rate and surface roughness in surface-electrical discharge diamond grinding process

Abstract

Metal matrix composites (MMCs) can be machined using electrical discharge machining (EDM) but the process is found slow. Electrical discharge diamond grinding (EDDG), which is a hybrid machining process (HMP) comprising of diamond grinding (DG) and electrical discharge grinding (EDG), has been found a viable machining method which enhances MRR and produce better surface finish. During EDDG, abrasive grains eradicate the non-conducting material particles of MMCs, and spark discharges thermally softened the surrounding binding material. In the present work, an attempt has been made for modelling of EDDG in surface grinding mode for outputs MRR and average surface roughness (Ra) and inputs wheel speed, depth of cut, workpiece speed, pulse on-time, current and duty factor. Experiments were carried out on a newly self-developed surface grinding setup for EDDG on a die sinking EDM machine for Al-10wt.%Al2O3 composite. Finally, weighted principal component (WPC) is proposed for optimising the machining parameters.