Fabrication of Carbon Fiber‐Reinforced ABS Composites via Fused Granulated Fabrication With In Situ Blending

ABSTRACT Traditional Fused Filament Fabrication (FFF) is constrained by fiber fracture and nozzle obstructions during the extrusion process in applications requiring higher fiber loading, hence limiting the complete realization of material capabilities. This work involves the preparation of chopped carbon fiber‐reinforced ABS composites (CF‐ABS) with carbon fiber contents ranging from 0 to 40 wt% via a Fused Granulated Fabrication (FGF) in situ blending 3D printing technique. A systematic investigation was conducted on the influence of fiber content on the mechanical characteristics, microstructure, and porosity of composites. The elastic modulus increased consistently with fiber concentration, attaining a maximum of 18.8 GPa at 40 wt% CF. The tensile strength exhibited an initial increase before declining, with a maximum value of 78.8 MPa observed at 30 wt% CF composites. This drop at 40 wt% is related to increased porosity and fiber agglomerates. Elongation at break dramatically decreased with increased fiber content; annealing treatment enhanced material density and somewhat improved strength, although it further reduced ductility. The microstructure exhibited favorable fiber alignment in the printing direction (Krenchel orientation factor > 0.94), despite the average fiber length being reduced from 406.2 to 115.1 μm during the process. The fiber pullout is regarded as the primary fracture mode. This study provides novel insights and theoretical guidelines for the additive manufacturing of CF‐ABS composites with high fiber content.