Parametric optimization of drilling on titanium grade-2 in die-sinking electrical discharge machining

Abstract

Electrical discharge machining (EDM) is one of the advanced machining processes basically used to produce three-dimensional features and complex cavities with various advantages resulting from its inherent characteristics of being non-contact and removing material by electro-thermal energy. This work mainly focuses on die-sinking EDM on titanium grade-2 using copper as tool electrode. Process parameters such as machining time (MT), pulse on time (Ton) and current are varied during experimentation. Taguchi L-8 orthogonal array has been incorporated to study the effect of process parameters on the response measures: material removal rate (MRR), tool wear rate (TWR) and overcut (OC). The process parameters have been optimized for higher MRR, and lower TWR and OC. Overall evaluation criteria (OEC) has been formulated to perform simultaneous optimization of the response measures. MRR of 0.68 mg/min, TWR of 0.22 mg/min and OC of 28.46 μm has been achieved at the optimum parametric condition of OEC. Further, analysis of variance (ANOVA) has been employed to evaluate the significance of process parameters on the response measures.