This study attempted to machine AA7050 using the Electric Discharge Machining (EDM) technique fabricated through stir casting, whereas aluminium oxide and silicon carbide particles were used as reinforcement. Experiments conducted by altering, powder concentration, current, pulse duration, and reinforcing %, machining performance evaluated in terms of material removal rate (MRR), Tool Wear Rate (TWR), surface roughness (Ra), and Machined Surface Hardness (MSH). Because of the high density, the suspension of Gr particles inside the spark gap was obstructed, causing particle deposition over the surface, which lowers the MRR in contrast to other particle suspensions. Lower heat was produced at higher Tons due to plasma densification, resulting in a drop in TWR. The Ra value improved as a result of the electrode’s higher gap distance from the workpiece, which enables thorough flushing of machined waste. The incorporation of particles also evenly distributed the energy over the machined area, eliminating the uneven machined surface. Black patches, resolidified solids, globules, craters, and pits were seen on the surface topography, when particles were introduced to the dielectric fluid, these defects were eliminated because of complete flushing of machined debris.

Keywords: PMEDM, Hybrid composites, Surface topography, Stir casting, Hardness.