The Mechanical Properties of 3D Printed Multiscale Hybridized Graphene Oxide and Short Carbon Fiber Reinforced Polyether‐Ether‐Ketone Composites

ABSTRACT Additively manufactured fiber reinforced polymer composites usually have weak interlaminar bonding properties and unsatisfactory improvements in mechanical properties. This study proposes a hybridized multiscale graphene oxide (GO) and short carbon fiber (SCF) reinforcement method to improve the bonding performance between the printing layers and then significantly enhance the mechanical properties of 3D printed polyether‐ether‐ketone (PEEK) composites. Firstly, the influence of GO content on the mechanical properties of GO/SCF/PEEK filaments was systematically studied. Then, by controlling the printing direction, the interface and mechanical properties were analyzed. By observing the orientation distribution of SCF and the microstructure of the composites, the enhancement mechanism of the multiscale hybridized GO‐SCF on mechanical properties was revealed. It is elucidated that the distribution of fillers was affected by the printing direction, resulting in obvious anisotropic mechanical properties. Benefiting from the filler alignment and improved interfacial bonding properties, the tensile strength and modulus of the 0.7 wt% GO/SCF/PEEK composite printed at 0° are respectively 12.9% and 14.3% higher than those of the SCF/PEEK composite, as well as 43.4% and 142.6% higher than those of pure PEEK. This method provides a theoretical basis for broadening 3D printed material systems and designing high‐performance PEEK composites with customized mechanical properties.