Investigating the electrical discharge machining (EDM) parameter effects on Al-Mg₂Si metal matrix composite (MMC) for high material removal rate (MRR) and less EWR–RSM approach

Al-Mg₂Si composite is a new group of metal matrix composites (MMCs). Electrical discharge machining (EDM) is a nonconventional machining process for machining electrically conductive materials regardless of hardness, strength and temperature resistance, complex shapes, fine surface finish/textures and accurate dimensions. A copper electrode and oil-based dielectric fluid mixed with aluminum powder were used. The polarity of electrode was positive. Response surface methodology (RSM) was used to analyze EDM of this composite material. This research illustrates the effect of input variables (voltage, current, pulse ON time, and duty factor) on material removal rate (MRR), electrode wear ratio (EWR), and microstructure changes. The results show that voltage, current, two-level interaction of voltage and current, two-level interaction of current and pulse ON time, and the second-order effect of voltage are the most significant factors on MRR. Pulses ON time and second-order effect of pulse ON time are the most significant factors affecting EWR. Microstructure analysis of EDM on Al-Mg₂Si samples revealed that voltage, current, and pulse ON time have a significant effect on the profile and microstructure of machined surfaced.