Multi-Feature Optimization of WEDM for Ti-6Al-4V by Applying a Hybrid Approach of Utility Theory Integrated With the Principal Component Analysis

In this study, multi-feature optimization is performed using a hybrid approach of utility theory (UT) combined with the principal component analysis (PCA) during wire electrical discharge machining (WEDM) of Ti-6Al-4V. Taguchi's L27 orthogonal collection is used to evaluate the effects of the pulse on time, pulse off time, peak current, servo voltage, wire feed rate and cable tension on surface roughness (SR), overcut and metal removal rate (MRR). The utility concept is employed to turn the multi-feature problem into a distinct equivalent feature called as overall efficiency index (OEI). Optimal sets of governing parameters using a hybrid approach are established as the pulse on time 114 machine unit, pulse off time 55 machine unit, servo voltage 20 volts, peak current 190 Amp., wire feed rate 5 m/min and cable tension 2 device unit. Scanning Electron Microscopic (SEM) analysis of cut surfaces shows a lump of debris, microvoids, micro-cracks, and large dark craters at high values of the pulse on time.