Parametric Study and Optimization of WEDM Process for Sustainable Machining of Hybrid Magnesium Metal Matrix Composites

In this study, two hybrid Magnesium-based metal matrix composites were fabricated using different proportions of reinforcements like Alumina (Al 2 O 3 ) and Silicon Carbide (SiC). Wire Electric Discharge Machining (WEDM) of these composites was carried out to evaluate the effect of pulse-on time, pulse-off time, current, and wire speed on cutting velocity, power consumption, surface roughness, and taper angle. Parametric analysis of the W-EDM process was conducted using a second-order regression model based on the Box-Behnken design approach. The Sustainability Index (SI) for WEDM of these fabricated composites has been developed. The study reveals that an increase in pulse on time at higher wire speed (10.4 m/s) reduces the TA up to 88% during WEDM of the composite containing a lower percentage of Al 2 O 3 and SiC. Similarly, the increase of wire speed from 3.12 m/s to 10.4 m/s at a low value of pulse-off time reduces TA by 85.95% in the composite containing a higher percentage of Al 2 O 3 and SiC. The optimal input parameters obtained through the optimization of SI give better machining results than output parameters obtained by optimization using GRA-PCA. The ANOVA analysis shows that the interaction effect of current with pulse off time and wire speed significantly affects the overall WEDM performance of magnesium composites. The confirmatory experiments for MMMC/2% Al 2 O 3 /4% SiC yield 39% higher CV while the PC, SR, and TA, respectively, reduce by 18%, 2%, and 74% compared to results given by the hybrid approach of GRA-PCA-RSM. Similarly, for MMMC/3% Al 2 O 3 /6% SiC, CV rises by 14.5%, whereas PC and SR reduce by 20% and 19%, respectively. The surface morphology reveals that both composites show lower microcracks and low agglomeration of reinforcement at the optimal parameters obtained by optimization of SI.