面向3D打印的连续碳纤维上浆工艺及其对复合材料性能的影响

Continuous fiber reinforced thermoplastic composites (CFRTPCs) by 3D printing technology can realize the rapid manufacture of complex composite parts without mold and promote the practical application of additive manufacturing. In order to further improve the service performance of 3D printed continuous carbon fiber reinforced composites, this paper adopted thermoplastic sizing agent to size dry carbon fiber, and printed continuous carbon fiber reinforced composites with nylon 6 (PA6) as the matrix, and compared the surface properties of carbon fiber before and after sizing and the mechanical and interface properties of the composites. The results showed that the polar functional groups on the surface of sized carbon fiber increased and the infiltration between fiber and resin improved. The surface roughness increased, and the mechanical adhesion between fiber and resin increased. The interlaminar shear strength of the sized carbon fiber reinforced PA6 composites was 42.2% higher than that of the non-sized carbon fiber reinforced; the interlaminar bonding was enhanced, the bending strength was improved by 82%, and the bending modulus was increased by 2.46 times. By comparing and analyzing the fracture microstructure of 3D printed composites, it is found that the fracture section of the sized carbon fiber reinforced composites had obvious fiber pull out phenomenon, and the interface performance was significantly improved.