MULTI-OBJECTIVE OPTIMIZATION OF MACHINING PARAMETERS FOR EDM OF MAGNESIUM ALLOY-ZE41 USING MARCOS ALGORITHM AND DIFFERENT WEIGHING METHODS: SD, CRITIC AND MEREC

Abstract

This paper presents multi-objective optimization of machining parameters, i.e., electrode materials, peak current, pulse on time and pulse off time in EDM of magnesium alloy-ZE41. The objectives such as metal removal rate, tool wear rate, surface roughness, recast layer thickness and radial overcut were optimized using MARCOS algorithm and three objective weighing methods, i.e., SD, CRITIC and MEREC. Taguchi’s L27(34) orthogonal array was used for conduction of experiments. ANOVA results showed that electrode material, interaction of electrode material and peak current and pulse on time were the most significant parameters for all weighing methods. Comparative study indicated that the percentage improvement in performance at optimal parameter setting were 37.21%, 32.30% and 10.68% for SD, CRITIC and MEREC respectively. Confirmation results indicated that all objectives except tool wear rate were improved positively for SD and CRITIC, but all objectives except metal removal rate deteriorated for MEREC.