Effect of process parameters on tensile properties of 3D printed continuous aramid fiber reinforced nylon 12 composites

Continuous fiber reinforced thermoplastic composites (CFRTP) have been increasingly used in aerospace and rail transport in recent years because of their high strength and light weight. In this paper, the effects of nozzle temperature, printing speed, substrate temperature and layer thickness on the tensile properties and macro/microscopic damage modes of CAF/PA12 printed specimens was systematically investigated. The fiber volume fraction(FVF) of CAF/PA12 filaments was 25.62%. The maximum average tensile strength and tensile modulus of CAF/PA12 printed specimens reached 572.60 MPa and 18.49 GPa, respectively. The results of the cross-sectional analysis indicated that filament toothed fractures and transverse cracks were the main macroscopic failure modes of CAF/PA12 composites. In SEM images, the main microscopic failure modes of CAF/PA12 composite are fiber fracture, fiber pull-out pores and unimpregnated fibers.