Optimization of WEDM Process Parameters for MRR and Surface Roughness using Taguchi-Based Grey Relational Analysis

Abstract

This article presents an experimental study of material removal rate (MRR) and surface roughness characteristics of wire electrical discharge machining (WEDM) and the optimization of process parameters based on Taguchi method coupled with grey relational analysis for minimum surface roughness and maximum MRR. Experiments are carried out by utilizing the combination of process parameters viz. discharge current, voltage, pulse on time and pulse off time based on L27 Taguchi orthogonal array (OA). Analysis of variance (ANOVA) carried out and it reveals that current has the maximum contribution in controlling MRR and surface characteristics of WEDM. The interaction between voltage and pulse on time is also found to have significant contribution in MRR and surface roughness characteristics. The optimum combination of process parameters for maximum MRR and minimum surface roughness is obtained and the optimal setting has been verified through confirmatory test. The result shows good agreement between the predicted and experimental results. This indicates the utility of the grey-Taguchi technique as multi-objective optimizer in the field of WEDM. Also, variation of responses with process parameters are also studied using 3D surface plots. Finally, the microstructure analysis in the region of cutting surface is performed using scanning electron microscopy (SEM).