Optimization of wire-EDM process of titanium alloy-Grade 5 using Taguchi’s method and grey relational analysis

Abstract

Wire-EDM is an unconventional machining practice that is extremely capable for precision machining of superalloys having high electrical conductivity. Titanium alloy Grade 5-Ti-6Al-4 V is a superalloy with an increasingly high demand in various industries such as the aerospace, biomedical and automobile industry by virtue of its high corrosion resistance, biocompatibility and high strength to weight ratio. The Wire-EDM operation becomes advantageous for machining of Ti-6Al-4 V if the input process parameters are optimised for attaining minimum surface roughness and maximum material removal rate. The methodology adopted for this optimization process is Taguchi’s Method coupled with Grey Relational Analysis. ANOVA has been done to analyse the efficacy of considered input specifications. The outcome reveals that peak current and pulse-off time have the highest contribution on the process performance. Material removal rate and surface roughness both increase with the increase in peak current as well as pulse-off time. Grey Relational Analysis imparts the optimal set of values of input parameters for achieving, in combination, maximum material removal rate and minimum surface roughness as 3A peak current, 30 µs pulse-on time and 9 µs pulse-off time.