Investigating the Interlaminar Shear Strength of Short Carbon Fiber-Reinforced PEEK Composites Fabricated by Fused Filament Fabrication

Abstract

Abstract Carbon fiber (CF)-reinforced polyetheretherketone (PEEK) composites are highly valued for their exceptional physical and mechanical properties, making them suitable for various industrial applications. This study aims to investigate the interlaminar shear strength (ILSS) of short CF-reinforced PEEK composites fabricated by the fused filament fabrication (FFF) technique. Short beam shear (SBS) tests were performed to quantify the ILSS of 3D-printed CF-reinforced PEEK composites and unreinforced PEEK as the baseline. The digital image correlation (DIC) technique was used during the tests to measure in-situ full-field strain maps, enabling the observation of interlaminar failure mechanisms. The role of CF reinforcement and infill line orientation between adjacent layers on the ILSS of the PEEK composites was analyzed. The research findings reveal two main points: firstly, by adding short carbon fibers to 3D-printed PEEK composites, known as CF-PEEK, their ILSS can be improved by up to 100%, making it more effective than standard PEEK. Secondly, increasing the mismatch angle θ between infill lines of neighboring layers enhances ILSS in both PEEK and CF-PEEK by up to 50%. These outcomes could enhance the mechanical properties of 3D-printed PEEK and CF-PEEK composites in industries that require strong, lightweight materials.