Evaluation of machining performance and multi criteria optimization of novel metal-Nimonic 80A using EDM

This study focused to machine novel Nimonic 80A through Electric Discharge Machine process. The process parameters are optimised to achieve high surface integrity along with high material removal rate (MRR) with minimum energy consumption. Central composite design along with analysis of variance technique has been applied to make correlation between the process parameter and responses. The developed model of surface roughness shows that the peak current and pulse-on time have significant effect whereas; a little effect of pulse-off time. The said result may be obtained due to simultaneous action of deposition and notching (removal) of material in order to form crater. In case of MRR, the pulse-on time and peak current are found as significant factors with increasing trend (i.e. when the input values are increased the MRR increases) whereas; a reverse trend is noticed with pulse-off time. The optimum values for maximum MRR (0.512444 gm/min) and minimum surface roughness (7.82203 µm) with 81% desirability are obtained for the process parameter as 13.49 A peak current, 150 µs pulse-on time and 4 µs pulse-off time.