Experimental investigation and multi-response optimization of electrical discharge machining parameters for EN24 steel using response surface methodology

Electrical Discharge Machining (EDM) is a nonconventional machining process used for machining difficult-to-cut materials and can produce complex geometries. However, maintaining a balance between productivity, surface integrity, and dimensional accuracy has always been an issue in high-precision manufacturing. This research aims to evaluate the impact of three parameters, which include Pulse-ON Time (T ON :100–200 µs), Pulse-OFF Time (T OFF :40–60 µs), and Peak Current (I P :10-20A), on six responses, which include maximizing the Material Removal Rate (MRR), minimizing Electrode Wear Rate (EWR), Dimensional Deviation (DD), Cylindricity (Cyl), Taper Angle (TA), and Surface Roughness (Ra). Experiments were carried out using Response Surface Methodology on EN24 steel using copper electrodes. This study innovates in simultaneously optimizing metrology-related responses in the context of productivity and surface integrity. The experimental results revealed that discharge energy significantly influences machining efficiency, surface integrity, and dimensional precision. Higher T ON and I P improved MRR, whereas lower discharge energy conditions enhanced surface finish and geometrical accuracy. The optimal parameters are: T ON = 171.731 µs, T OFF = 60 µs, and I P = 16.8101 A. Apart from being technically innovative, this work supports SDGs, which include SDG 9 in relation to precision manufacturing and SDG 12 regarding minimized waste of materials and energy.