EDM drilling of Inconel 718, ss304, and en24 materials under plain and hybrid nanoparticle-mixed dielectric conditions

In electric discharge machining (EDM), conductive nanoparticle-mixed dielectrics showed better machining performance, although their impact on eco-performance indices for different engineering materials using hybrid nanoparticle-mixed dielectrics remains less explored. With this view, this study investigates EDM drilling of Inconel 718, SS304, and EN24 materials by varying pulse-on time, discharge current, and gap voltage, utilizing both plain and hybrid nanoparticle mixtures of graphene and aluminium oxide in the dielectric. Discharge current and pulse-on time notably influenced EDM performance, particularly with Inconel 718 and SS304 in plain dielectric conditions. Compared to conventional dielectrics, nanodielectrics demonstrated a 34.97% improvement in material removal rate, a 25.92% reduction in surface roughness, a 77.15% decrease in tool wear rate, and a 22.01% lower roundness error. Additionally, energy consumption was reduced by 18.11%, contributing to an 18.6% increase in overall eco-index. Reduced recast layer formation further confirmed enhanced thermo-physical interactions with nanodielectric, suggesting improved eco-performance for EDM.