Experimental investigation and Taguchi-based multi-response optimization of EDM parameters for Stir-Cast Al6061–SiC composite with surface morphology analysis for aerospace applications

Electrical Discharge Machining (EDM) is widely used for machining electrically conductive materials with complex geometries. This study investigates the influence of key EDM parameters of pulse-on time, pulse-off time, and peak current on the machining performance of stir-cast Al6061–SiC composite. A Taguchi L9 orthogonal array was employed to design experiments and optimize process parameters. The performance characteristics, including Material Removal Rate (MRR), Tool Wear Rate (TWR), and surface roughness (SR), were evaluated using signal-to-noise (S/N) ratio analysis. The results indicate that peak current significantly affects MRR, while pulse-on time predominantly influences TWR and SR due to variations in discharge energy. Optimal conditions for maximum MRR were identified at 15 A current, 75 µs pulse-on time, and 40 µs pulse-off time, whereas lower current levels favored reduced TWR and improved surface finish. SEM analysis revealed typical EDM features such as craters and recast layers, with surface damage increasing at higher discharge energies. Confirmation experiments showed good agreement with predicted results, validating the optimization approach. The study is limited to machining performance and qualitative surface analysis, and does not include detailed thermal modeling or mechanical property evaluation. The findings provide useful insights into EDM parameter optimization for aluminum-based composites under controlled conditions. Optimization of Electrical Discharge Machining (EDM) parameters using the Taguchi L9 orthogonal array to enhance machining quality. Investigation of pulse on time, pulse off time, and peak current effects on MRR, TWR, surface roughness, and hardness of stir-cast Al6061–SiC composite. Comprehensive surface characterization using Scanning Electron Microscopy (SEM) to evaluate EDM-induced surface topography modifications Identification of optimal machining conditions for improved performance of stir-cast Al6061 (6.5% SiC) composite using a copper electrode.