Numerical and experimental investigation of orthogonal cutting of carbon fiber-reinforced polyetheretherketone (CF/PEEK)

Carbon fiber-reinforced thermoplastic composites have gained much attention due to their excellent mechanical properties, corrosion resistance, short curing process, and easy recyclability. However, the current research on the machining of composites is mainly focused on the thermoset composites, and the influence of the thermoplastic matrix on the machining performance of the composites is still unclear. In this paper, orthogonal cutting experiments of carbon fiber-reinforced polyetheretherketone (CF/PEEK) were carried out and a 3-D micro numerical cutting model with considering the strain-rate-dependent mechanical properties of PEEK was established as well. The cutting force, fiber failure and machining damages predicted by the proposed model agree well with the experimental results. Based on the experimental and numerical simulation approaches, the effects of fiber orientation angles ( $$\theta$$ ) and depth of cut ( $${a}_{c}$$ ) on the cutting mechanism, cutting force, and surface integrity of CF/PEEK were investigated in detail. The results indicate that fiber orientation is still the dominant factor in the CF/PEEK machining process; however, compared to the machinability of carbon fiber-reinforced thermoset composite, the certain ductility of PEEK matrix leads to continuous curly chip formation and differences in machined surface quality. Meanwhile, the machining damage formation mechanism was studied through a combination of experimental and simulation approaches.