Enhancing Drilling performance in Hybrid Basalt/E-Glass Fiber Epoxy modified with MWCNTs + SiO₂ Nanocomposites

Recently, the utilization of hybrid basalt/glass fiber reinforced polymer (HBGFRP) nanocomposites has increased significantly in structural applications due to their light weight nature, superior strength-to-weight ratio, and excellent mechanical, chemical, and thermal properties. This study aims to investigate the effects of various drilling parameters and filler weight content on delamination and surface roughness on HBGFRP nanocomposites filled with combination of multi-walled carbon nanotubes (MWCNTs) and nano-silica particles (SiO₂) in equal weight proportions of 0%, 1%, and 2%. These nanocomposite laminates were fabricated using the manual lay-up method followed by compression molding with a novel stacking order of fibers 0₁^B/0₂^G/0₂^B/0₂^G/0₂^B/0₂^G/0₁^B consisting of 12 layers.. In this work, the Box-Benkhen Design of Response Surface Methodology (RSM) was employed to optimize the drilling parameters, including spindle speed, feed rate, drill diameter, and weight content of MWCNTs + SiO₂. The nanocomposites containing 1.0wt. % MWCNTs + SiO₂ demonstrated the most significant reduction in the delamination factor, achieving a 24% reduction. The lowest delamination factor recorded was 1.29, obtained with a spindle speed of 1350 rpm, a feed rate of 0.1 mm/rev, a drill diameter of 6 mm, and the addition of 1.0wt. % MWCNTs + SiO₂. Increasing the spindle speed resulted in a further reduction in the delamination factor. The surface roughness measured was 1.213 µm, indicating a relatively smooth surface. It was evident that increase in feed rate and drill diameter corresponded to increase in both delamination factor and surface roughness.