Understanding the role of weight percentage and size of silicon carbide particulate reinforcement on electro-discharge machining of aluminium-based composites

This study investigates the feasibility of fabricating microholes in SiCp-Al composites using micro-electro-discharge machining (micro-EDM) with a rotary tube electrode. Material removal rate (MRR), electrode wear rate (EWR), and hole taper were considered as responses for the study. Machining was performed on 5 and 10 wt% SiC(p)-Al composites having particle size of 50m and 150m to evaluate machining characteristics. Pulse-on duration, pulse-off duration, sparking gap voltage, and servo-speed were used as input variables for EDM of SiC(p)-Al composites by varying the weight percentage of SiC-reinforced particles and the size of reinforcement. The experimental results indicate the weight percentage and size of the SiC in SiC(p)-Al metal matrix composites (MMCs) to be important parameters while machining using micro-EDM. The relative contributions of each process variable on MRR, EWR, and hole taper were found using the analysis of variance (ANOVA) technique. The experimental results reveal that servo-speed significantly affects the MRR and EWR, while pulse-on duration affected the taper.