Thermo-mechanical stability and damage evolution in drilling of multiscale bamboo–graphene epoxy composites: Experimental–statistical correlation for high-fidelity hole making

The thermally mechanical resilience and damage development during drilling of alkali-treated bamboo powder–graphene nanoplatelet (GNP)-reinforced epoxy composites are examined in this work. In order to allow high-fidelity hole creation in environmentally conscious multiscale composites, this study is innovative in that it establishes an experimental–statistical link between drilling conditions, force production, surface integrity, and damage progression. Drilling trials were carried out with various drill diameters, feed rates, and spindle speeds. To assess machining efficiency and improve drilling settings, real-time thrust force, surface roughness, circularity error, SEM-based damage characterization, ANOVA, and response surface methodology (RSM) were used. The findings indicated that although spindle speed controlled surface roughness (63.88%), feed rate mostly affected thrust force (37.24%) and circularity error (>41%). Under extreme machining operating conditions, SEM studies showed matrix degradation, fiber pull-out, localized debonding, and fracture progression. High prediction precision for drilling reactions was shown by the constructed RSM models. The research provides a useful paradigm for enhancing precision drilling of sustainable composites by establishing a mechanical link between drilling-induced degradation and hybrid reinforcing design. The results validate the industrial use of bamboo-graphene epoxy composites in precision-built engineering items that need high-quality hole fabrication, such as lightweight automobile components, aircraft secondary structures, and green infrastructure.