The study proposes a novel method, named angled feeding extrusion (AFE), for material extrusion additive manufacturing (MEX AM) of discontinuous recycled carbon fibre (rCF) reinforced thermoplastic composites with high fibre efficiency. The AFE system is also integrated with a 5-axis printer to enable the fabrication of complex structures. Characterisation of fibre morphology and structure is conducted using X-ray computed microtomography (μCT), and the mechanical properties of the AFE-manufactured rCF composites are investigated through mechanical testing. The results show that AFE demonstrates effectiveness in reducing the fabrication difficulty of rCF composites with high fibre efficiency, fibre efficiency encompasses factors such as fibre fraction, length, and orientation. Moreover, rCF composites additively manufactured by the AFE system achieve rCF lengths of up to 3.8 mm and a fibre volume fraction of 30.3 %. The tensile strength and modulus are 178 MPa and 9.9 GPa respectively. It exhibits a significant improvement of 90 % and 254 % in tensile strength and modulus compared to short fibre reinforced composites. Similarly, compressive tests of AFE-manufactured composite rings show an increase of 80 % in ultimate compressive load.
Pour en savoir plus : Document details – Material extrusion additive manufacturing of recycled discontinuous carbon fibre reinforced thermoplastic composites with high fibre efficiency