Multi Response Optimization of Powder Mixed Electric Discharge Machining of Aluminum/Alumina Metal Matrix Composite Using Grey Relation Analysis

Abstract Electric discharge machining (EDM) is a well-established non-conventional machining process for the machining of electrically conductive and difficult-to-machine materials. But its applications are limited because of slow machining rate and relatively poor surface finish. Powder mixed EDM (PMEDM) is one of the recent advancements in EDM process where the addition of powder particles to the dielectric results in higher machining rate and better surface quality. In this work, Aluminum/Alumina metal matrix composite (MMC), which has many applications in automobile and aero-space industry, was fabricated and machined in EDM by mixing aluminum powder in kerosene dielectric. The effect process parameters (powder concentration, peak current, pulse on time and duty cycle) on two responses namely, material removal rate (MRR) and surface roughness (SR) were measured. A multi response optimization was performed using grey relational analysis (GRA) to find the optimum combination of the process parameters for maximum MRR and minimum SR. The results show that the powder concentration of 6 g/L gives the optimum result for the multi responses.