Electrical Discharge with an effort to create wealth out of waste, Used Engine Oil (UEO) was employed as the dielectric medium to machine AA7075 hybrid composites. The research was conducted utilizing a variety of tools (Copper, Brass), current, pulse, weight percentage of composites, and powder concentration. The experimentation was designed using a Taguchi L18 orthogonal array. Because of its superior heat conductivity, copper electrodes remove more material than brass electrodes. As the particle absorbs the most amount of heat generated, MRR falls as Cu particle integration increases to 6 g/l. Cu powders added to the dielectric medium increase TWR, and research indicates that the heat created was transferred to the electrode rather than the work piece. Particles used as reinforcement had no impact on TWR. Brass electrode had a lower thermal conductivity than the copper electrode, less material was removed, resulting in the best surface quality. The formation of remelted layers is halted by through flushing, which is brought on by widening the spark gap. Due to the heat-absorbing qualities of copper particles, the surface is exposed to lower temperatures, increasing the surface's quality by preventing the formation of cracks and craters. In the case of tools made of copper, 3 g/l of conductive copper powder was added to the dielectric fluid, and the current, pulse on time, and pulse width were all set at 3A and 15 µs, maximum productivity was achieved.

Keywords: EDM, Optimization, Wealth from waste, PMEDM, Surface topography.