Effect of copper-graphite composite electrode on material removal rate and surface roughness in MONEL 400 during electrical discharge machining

Electrical Discharge Machining (EDM) is one of the non-traditional machining processes commonly used for machining of hard to cut metals. Monel 400 is a nickel based superalloy used in various applications. The composite electrode is developed and applied to enhance the machining process by reducing the time of the process and the cost of the electrode manufacturing. The presented work is aimed to study the effect of copper, graphite, and copper-graphite composite electrodes with different parameters on the Material Removal Rate and Surface Roughness of Monel 400. Influences of discharge current (Ip), pulse on time (Ton), and pulse off time (Toff) have been investigated. Based on the Taguchi method, experiments were analyzed using ANOVA through Minitab 20. The results have manifested that compared to copper and graphite electrodes, the copper-graphite electrode achieved better values of material removal rate and surface roughness. The lowest value of surface roughness is 3.1413 μm as a result of the added graphite reinforcement particles.