Additive Manufacturing of Continuous Carbon Fiber Reinforced Polymer Composite with Graphene Enhanced Interface Bond

Laser-assisted laminated object manufacturing (LA-LOM) is proposed to fabricate continuous carbon fiber reinforced polymer composites (CFRPCs) based on the prepreg sheets with continuous carbon fiber reinforcement. Their mechanical performances depend on the interfacial properties of the bonded prepreg sheets. In this investigation to improve the mechanical properties of 3D printed CFRPCs, graphene is introduced as a modifier between the prepreg sheets. The effect of graphene content on interlaminar shear strength of the printed samples is investigated by lap shear tests, and the optimum content of 0.5 mg/ml is obtained. The low porosity (0.379 %), high concentrations of continuous carbon fibers (63 wt.%) and improved interfacial bonding strength contribute to the excellent mechanical properties. For the CFRPCs samples with the fiber arrangements of [0°]_s, the lap shear strength increases by 25.7 %, flexural strength increases by 9.9 % and flexural modulus increases by 26.5 %, while the tensile strength increases by 6.8 % and modulus increases by 9.9 % when 0.5 mg/ml graphene introducing to the laminated composites. The improvement of mechanical properties is due to mechanical interlocking of graphene with epoxy resin and carbon fibers. The graphene enhancement is one of the applicable methods to improve the properties of carbon fiber-reinforced polymer composites.