Optimization of Tool steel

Electro Discharge Machining (EDM) is a widely adopted non-traditional machining process used for shaping hard and electrically conductive materials, particularly tool steels. The present study focuses on optimizing the EDM process parameters for tool steel (D3) using a Grey-based Taguchi method to achieve improved machining performance. The primary objectives are to maximize the Material Removal Rate (MRR) while minimizing the surface roughness (Ra). Experiments were conducted on an ELECTRAPULS PS 35 EDM machine, utilizing copper electrodes with varying process parameters: voltage, current, and pulse-on time. A Taguchi L9 orthogonal array was employed to design the experiments. Grey Relational Analysis (GRA) was then applied to convert multi-response performance characteristics into a single Grey Relational Grade (GRG), facilitating multi-objective optimization. The results revealed that the optimal combination of process parameters for multi-performance characteristics was 70 V, 18 A, and 150 μs pulse-on time. The study confirms the effectiveness of integrating Taguchi design and GRA for simultaneous optimization of MRR and surface roughness in EDM, providing valuable insights for industrial applications and future research in advanced machining processes.