Impregnation and interlayer bonding behaviours of 3D-printed continuous carbon-fiber-reinforced poly-ether-ether-ketone composites

Continuous carbon-fibre-reinforced poly-ether-ether-ketone (CCF/PEEK) composites have garnered particular attention owing to the excellent thermal-assistance, corrosion-assistance and mechanical properties. In this study, CCF/PEEK composites were first prepared by extrusion three-dimensional (3D) printing. Interlayer delamination as a major factor limits the performance of thermoplastics extrusion 3D printing, and is exacerbated owing to the introduction of continuous fibres in this process. To overcome the interlayer delamination, the impregnation behaviours between carbon fibre tow and PEEK were studied by adjusting the viscosity of matrix materials and implementing pre-impregnation, while the interlayer bonding behaviours in different laser preheating temperatures were studied subsequently. Sufficient impregnation and the improved interlayer bonding of CCF/PEEK composites was effectively realised. The interlaminar shear strength and flexural strength of the CCF/PEEK composites can reach over 35 MPa and 480 MPa respectively, which gives a promising candidate for the preparation of complex structural parts in aviation and aerospace as a metal replacement.