Multi-Objective Optimization for the Sustainable Machining of Metal Matrix Composites Using Wire Electric Discharge Machining

Abstract

Wire Electrical Discharge Machining (WEDM) is an electrothermal machining process used to produce complex profiles electrically conductive materials. In this investigation, multiobjective optimization using hybrid approach of Taguchi method (TM) and Principal Component Analysis (PCA) has been performed to find the optimal input process parameters like pulse-on time ([Formula: see text]), pulse-off time ([Formula: see text]), peak current (I), wire speed (WS) for output parameters, namely, cutting velocity (CV), power consumption (PC), and surface roughness (SR). Three different Aluminum based Metal Matrix Composites (AMMC) were fabricated using three different reinforcements i.e. 10[Formula: see text]wt.% Aluminum Oxide (Al2O3), 10[Formula: see text]wt.% Silicon Carbide (SiC), and combining 5[Formula: see text]wt.% Al2O3 with 5[Formula: see text]wt.% SiC through the stir casting process. The experiments were conducted based on the L9 orthogonal array approach of Taguchi methodology and regression equations were developed based on the experimental data for the prediction of output parameters. The results of analysis of variance (ANOVA) shows that WS and I are the two most significant factors for CV of all three developed composites whereas for SR, [Formula: see text] and I play critical role. The optimal results show that for machining of Al6061/Al2O3 and Al6061/SiC optimal input parameters are [Formula: see text][Formula: see text][Formula: see text]s, [Formula: see text][Formula: see text][Formula: see text]s, [Formula: see text][Formula: see text]A, and [Formula: see text][Formula: see text]m/s. For hybrid MMC (Al6061/Al2O3/SiC), optimized input parameters are [Formula: see text][Formula: see text][Formula: see text]s, [Formula: see text][Formula: see text][Formula: see text]s, [Formula: see text][Formula: see text]A, and [Formula: see text][Formula: see text]m/s. At optimal input parameters though the CV decreases by 1.53% the PC and SR decreases by 8.95% and 15.47%, respectively, in case of hybrid composite. The machined surface at optimal input parameters were examined by the Scanning Electron Microscope (SEM). This study will help to identify the input parameters for sustainable machining of AMMC for different reinforcements with WEDM.