Strengthening and toughening behaviours and mechanisms of carbon fiber reinforced polyetheretherketone composites (CF/PEEK)

Carbon fiber reinforced polyetheretherketone (CF/PEEK) has vast application prospects in orthopedic implants. In practical applications, excellent tensile, bending and impact properties are indispensable for orthopedic implant materials. The pressure-induced flow (PIF) process markedly and simultaneously improved the strength and toughness of CF/PEEK by forming a multilayer-oriented structure, which controlled the propagation of cracks and the tortuous energy dissipating paths. In this paper, short carbon fiber (6 wt%) reinforced PEEK composites were molded at different desired temperatures and pressures to adjust the efficiency of mechanical enhancement. The mechanical properties of CF/PEEK samples were investigated, and the corresponding mechanisms for the improvement of mechanical properties were proposed. The results of the study showed that the maximum tensile strength, flexural strength and compact strength of the materials could reach 157.3 MPa, 382.0 MPa and 7.7 KJ/m2, respectively.