Modeling of WEDM parameters and surface integrity characteristics in the machining of Nimonic75 alloy

In this paper, an attempt has been made to design a mathematical regression model of wire electric discharge machining (WEDM) parameters for surface roughness during machining of Nimonic75 alloy using the response surface methodology (RSM) and desirability function approach for multi-response optimization. Through analysis of variation, it has been reported that pulse on time is the most significant parameter affecting the surface roughness (Ra) followed by peak current. The desirability approach optimal parameters setting for minimum Ra are a pulse on time = 0.6 mu s, pulse off time = 46 mu s, servo voltage = 55 V and peak current = 80A. The confirmation results show the goodness of the developed model. Energy dispersive spectroscopy spectra found the migrated elements (i.e., Zn, O, and Cu) into the machined surfaces. Using scanning electron micrograph, the surface morphology of the machined surfaces has been examined. (C) 2020 Elsevier Ltd. All rights reserved.