Multi-objective optimization of material removal rate and surface roughness in electrical discharge turning of titanium alloy (Ti-6Al-4V)

Abstract

Electrical discharge turning (EDT) is a unique form of electrical discharge machining (EDM) process, which is being especially developed to generate cylindrical forms and helical profiles on difficult to machine materials at both macro and micro levels. This study presents an experimental investigation of electrical discharge turning of titanium Ti-6Al-4V alloy. The objective is to investigate the influence of machining parameters including polarity, pulse-on time, peak current, gap voltage and spindle speed on performance characteristics. Taguchi-grey relational approach based on multi objective optimization has been used to maximize material removal and to minimize surface roughness. It has been found that polarity followed by peak current has most influent nature in EDT process. The confirmation experiment shows an improvement in material removal rate of 12.70% and surface roughness of 5.57% through this approach.