Investigating Micro‐Electrical Discharge Drilling of Carbon‐Aramid Hybrid Composite

ABSTRACT Hybrid composites like carbon‐aramid hybrid composites (CAHC) present significant challenges during conventional drilling due to delamination, fiber pull‐out, and excessive tool wear. Micro‐electrical discharge drilling (μEDD), an electrothermal energy‐based non‐contact method, can be ideal for precision micro‐hole production in CAHC. The μEDD of CAHC and subsequent multi‐response optimization using Shannon Entropy integrated with the combined compromise solution (CoCoSo) method are presented in this work. The analysis of variance (ANOVA) demonstrated that voltage had the most significant impact on the variability of the output responses. The optimal combination of input parameters as per CoCoSo approach was voltage ( V ) = 140 V, pulse on time ( P on ) = 20 μs, and tool speed (TS) = 300 rpm. The values of material removal rate, dimensional deviations at entry and exit, and hole taper at the optimal setting were 1.8 mg/min, 122.10 μm, 44.02 μm, and 0.03253, respectively. Dimensional deviation was more prominent at the entry of the hole due to lateral sparking. The study concludes that μEDD combined with CoCoSo‐based optimization can yield precise micro‐features in CAHC.