Performance Studies on the Wire Electric Discharge Machining Characteristics of Stellite-6B Superalloys

Wire electric discharge machining (WEDM) is a specialized, electrothermal, nontraditional process to machine complex shapes. The aim of this research is to optimize the WEDM operating attributes with the objective of achieving a maximum material removal rate (MRR) and minimum roughness of the machined surface (Ra) for a stellite (6B grade) alloy. Taguchi experimentation (L₂₇) was carried out to determine the influence of machining attributes on the output responses. The influence of process attributes was studied using an analysis of variance (ANOVA) concatenated with grey relational analysis and the fuzzy logic concept. Scanning electron microscopy was performed to characterize the recast layer on the machined surface. Based on multiple objective criteria for achieving the maximum MRR and minimum Ra, the optimal coalition of process attributes was 80 μs pulse-on time, 10 μs pulse-off time, 3 m/min wire feed rate, 5 A peak current and 40 μm/s bed speed.