In this study, AA7050/SiC/B₄C hybrid composites were machined using the Electric Discharge Machining process, used engine oil as the dielectric fluid to obtain wealth from waste. The experiments were conducted by varying Silicon Carbide (SiC) powder concentration, electrode material (copper and brass), discharge current, pulse on time and reinforcement wt%. The Material Removal Rate (MRR), Tool Wear Rate (TWR), Surface Roughness (Ra) and machined surface hardness were recorded as responses. The inclusion of SiC particles increases the MRR because of the bridging effect, whereas the Ra value was improved due to the complete flushing of the dielectric fluid. Owing to the existence of carbon content in used engine oil, black spots were found on the machined topography. The specimens machined with a brass electrode offer better machining performance as compared with those machined with a copper electrode. The results revealed that the MRR, TWR and Ra upsurge with the intensification of discharge current and pulse on time. Owing to the absence of a re-melted layer, composites with lower machined surface hardness have a higher surface finish. The parameters were optimized using the TOPSIS method, and it was found that under used engine oil dielectric medium with a powder concentration of 3 g l⁻¹, parametric value sets of pulse on time 45 s, current 6 A, and machined with brass electrode offers superior machining efficiency.

在本研究中，AA7050/SiC/B ₄C 混合复合材料使用放电加工工艺进行加工，使用发动机油作为介电流体，从废物中获取财富。实验是通过改变碳化硅 (SiC) 粉末浓度、电极材料（铜和黄铜）、放电电流、脉冲开启时间和增强物重量百分比来进行的。材料去除率 (MRR)、刀具磨损率 (TWR)、表面粗糙度 (Ra) 和加工表面硬度被记录为响应。由于桥接效应，包含 SiC 颗粒会增加 MRR，而由于完全冲洗介电流体，Ra 值得到改善。由于使用过的发动机油中存在碳含量，因此在机械加工的地形上发现了黑点。与使用铜电极加工的试样相比，使用黄铜电极加工的试样具有更好的加工性能。结果表明，随着放电电流和脉冲准时的增加，MRR、TWR和Ra升高。由于没有重熔层，加工表面硬度较低的复合材料具有较高的表面光洁度。采用TOPSIS法对参数进行优化，发现在使用粉末浓度为3g的发动机油电介质下^-1，脉冲开启时间45 s，电流6 A 的参数值组，用黄铜电极加工提供了卓越的加工效率。