Analysis of wire-cut electric discharge machining behaviour of AA6061 / C / ZrO2 hybrid nano composites using Taguchi’s method

Abstract

This study focuses on the optimization of wire-cut electric discharge machining (WEDM) process for hybrid metal matrix nanocomposites. AA6061 alloy reinforced with graphene (C) and zirconia (ZrO2) was fabricated through the stir casting method with ultrasonic assistance for three different weight proportions: 92% AA6061 / 3% C / 5% ZrO2, 87% AA6061 / 3% C / 10% ZrO2, and 82% AA6061 / 3% C / 15% ZrO2. Microstructural examination confirmed the uniform distribution of reinforcements in the matrix alloy. The fabricated composite was machined by WEDM using an L27 orthogonal array designed by Taguchi’s method. Four electrical control factors of pulse on-time, pulse off-time, wire feedrate and peak current were considered, along with one reinforcement factor and three output responses: kerf width, surface finish and material removal rate to analyse the machining behaviour. Analysis of Variance was performed to determine the significant parameters. The results revealed that the most significant factor is pulse on-time among the five different factors. Optimized parameters were identified and examined through confirmation experiments resulting in improved machining characteristics.