Machining Performance Analysis in Electrical Discharge Machining of Alloy Tool Steel

This article primarily focuses on studying and analyzing the effect of machining parameters, viz., pulse on time (T_ON), pulse off time (T_OFF), and pulse current (I_p) on machining performance in terms of surface roughness (Ra) and material removal rate (MRR) during electrical discharge machining (EDM) of alloy tool steel (SKD11 steel). The traditional trial-and-error methods used to derive empirical relationship and optimize the process is time consuming and results in reduced productivity, high rejection, and cost. The response surface methodology (RSM) approach of design of experiment technique was applied for designing the experiments. The influences of EDM parameters on Ra and MRR were investigated using different graphs. The mathematical model equations for Ra and MRR were generated. The optimum parametric combinations for smaller Ra (highest surface finish) and highest MRR were found, and the optimized values of Ra and MRR were obtained. The predicted values showed close agreement with the experimental ones. The surface morphology of the machined surface was examined using a scanning electron microscope (SEM).