A strategic approach to drill CFRP composites via configural modifications into ECDM process

This study introduces a strategic methodology for drilling carbon fiber–reinforced polymer (CFRP) composites by modifying the Electrochemical Discharge Machining (ECDM) process. This study assessed the effects of workpiece insulation, tool geometry, and magnetic-field assistance. Insulating the CFRP facilitated localized bubble formation and spark discharges near the tool, thereby reducing the critical voltage and current and enabling through-hole formation with diminished delamination. A diamond-textured tool produced distributed discharges and offered additional abrasive action, leading to a higher material removal rate, reduced hole overcut, and enhanced edge quality compared with a conventional drill-bit tool. The incorporation of magnetic-field-assisted ECDM further improved the electrolyte circulation via magnetohydrodynamic action, disrupted bubble accumulation, stabilized the gas film, and promoted uniform low-intensity discharges. While an increase in voltage enhanced material removal, it also resulted in greater overcut and delamination, particularly in thicker laminates. In summary, the combined application of insulation, diamond texturing, and magnetic assistance markedly enhanced the drilling stability, dimensional accuracy, and hole quality of CFRP composites.