A review on CFRP drilling: fundamental mechanisms, damage issues, and approaches toward high-quality drilling

Carbon fiber reinforced polymer (CFRP) composites have become increasingly attractive in modern industrial fields in view of their unique properties and superior functionalities. CFRP composites are extremely tough to drill due to their inherent anisotropy and heterogeneity. The present paper aims to report the state-of-the-art progress in the mechanical drilling of CFRP composites through a rigorous literature survey. It covers the crucial aspects of drilling CFRP laminates, including drilling mechanisms, thermo-mechanical responses, drilling-induced damages, and the effects of various process conditions. The fundamental chip removal and damage formation modes of CFRPs are discussed. Results indicate that high cutting speeds and low feed rates improve the hole quality of CFRPs. Optimizing process parameters, developing suitable tool geometries/materials, and applying proper cutting environments will be an effective means to suppress the drilling damage of cut CFRP holes. More future research endeavors are expected to focus on revealing the mapping mechanisms between tool geometries/materials, cutting environments, process parameters, and CFRP hole-making quality and on proposing a comprehensively optimized hole-making strategy for high-quality drilling of CFRPs.