Electric Discharge Machining (EDM) is an alternative machining process to traditional machining process for the precise machining of complex shaped electrically conductive machine parts. The main objective of this research work is to study the impact of EDM conditions (Pulse on time, peak current, voltage and types of dielectric) on SR during machining of AISI 4140 steel using RSM based on face centered design. Also an effort is made with optimized EDM conditions to formulate the relationship between machining conditions and responses for desired responses. The SEM analysis has also been carried out to examine the surface morphology of machined surfaces of test specimens. The pulse on time, peak current, voltage, and types of dielectric are found significant EDM conditions that affect the SR. The SR is directly proportional to pulse on time & peak current for both Kerosene and deionized water as dielectric fluid. Also, the prediction ability of the developed model has been found significant.

Keywords : EDM , SEM, Surface Roughness, Dielectric Fluid.