Multi-objective parametric optimisation during electrical discharge machining of Inconel 718 with different electrodes

Abstract

This paper presents multi-objective parametric optimisation of electrical discharge machining (EDM) process by the Taguchi method with grey relation analysis. Experimental investigations are performed on Inconel 718 with three different electrodes. Orthogonal array (L36) is used to identify the effect of process parameters (viz. polarity, electrode type, peak current, pulse on time, duty cycle, gap voltage, retract distance and flushing pressure) on the performance characteristics in terms of material removal rate surface roughness and tool wear rate. Using grey relational analysis, grey relational grade has been determined, which effectively represents the aggregate of different process attributes. As a result, a multi-objective parametric optimisation is converted into optimisation of a single grey relational grade. Experimental results have shown that utilisation of optimal machining parameter combination enhances a significant improvement of the grey relation grade and the grey relation grade is improved by 8.72%.