Experimental investigation of fused filament fabrication process parameters on the mechanical performance of carbon fibre reinforced PEEK composites

This study investigates the feasibility of processing carbon fibre-reinforced polyetheretherketone (CF-PEEK) using fused filament fabrication (FFF) for high-performance applications in aerospace, biomedical, and industrial sectors. The objective is to evaluate the influence of key FFF process parameters, including extrusion temperature, printing speed, layer height, and infill density, on the mechanical and thermal performance of CF-PEEK components. In this work, tensile strength, fatigue life, and thermal stability of printed CF-PEEK parts are systematically investigated. In addition, the effects of fibre-matrix bonding quality and fibre orientation on mechanical performance are examined. The experimental results demonstrate that lower extrusion temperatures, reduced printing speeds, and higher infill densities significantly enhance tensile strength and fatigue resistance. Under optimised conditions, CF-PEEK exhibits a tensile strength of 105 MPa and a fatigue life exceeding 1.2 × 10⁵ cycles, outperforming neat PEEK. Finite element analysis (FEA) shows good agreement with experimental observations, with predicted stress and strain values deviating by less than 9 percent, confirming the reliability of the numerical model. Overall, the findings confirm that FFF-processed CF-PEEK is a viable lightweight and fatigue-resistant material for aerospace, automotive, and biomedical applications, while also establishing a robust process-structure–property foundation for data-driven optimisation of high-performance polymer additive manufacturing.