Parametric Optimization of EN-31 Steel Using Electric Discharge Machining

This investigative study conducted parametric optimization of EN-31 steel using Electric Discharge Machining (EDM). EN-31 is a high-rigidity alloy essential to aerospace and automotive manufacturing. The primary objective was to analyze the impact of input factors—Pulse on Time (Ton), Pulse Off Time (Toff), Current (LV), and Voltage (HV)—on five output responses: Machining Time (Tm), Material Removal Rate (MRR), Electrode Wear Rate (EWR), Surface Roughness (Ra), and Base Radius (R). The study utilized a full factorial Design of Experiment (DOE) approach and ANOVA to determine significant factors and optimal settings. Results showed that for Tm, LV and Ton were significant, achieving an optimized time of 654.29 seconds at 50 A and 6.5 µs. Ton was the primary factor for MRR, yielding a maximum of 0.0157 g/min at 6.5 µs. For EWR, minimal wear of 0.07 g/min was achieved with LV at 30 A and Ton at 4 µs. Optimizing Ra required a combination of all factors to achieve a minimum of 0.018 mm. Additionally, Base Radius optimization resulted in 1.5 mm using specific combined settings. This optimization facilitates higher productivity, superior surface finishes, and lower manufacturing costs for EN-31 parts