Additive manufacturing of quasi-isotropic wire-reinforced metal-polymer composite laminates

Purpose The purpose of this study is to demonstrate the viability of dual extrusion fused filament fabrication to manufacture polymer matrix composite laminates reinforced with large diameter (300 µm) metallic wires. Design/methodology/approach A dual extrusion technique – in which polymer layers and wire layers are sequentially deposited – was used to manufacture unidirectional [0º]₄, cross-ply [± 45º]_s and quasi-isotropic [0º/90º/± 45º]_s laminates of PLA reinforced with 20 Vol.% Al wires. Findings X-ray microtomography was used to assess the microstructure of the laminates, and it was shown that wire orientation and volume fraction could be accurately controlled while the porosity within the laminates was minimum. However, the adhesion between the matrix and the wires was poor, and this led to early interfacial fracture when loaded perpendicular to the wires. Overall, the strength and ductility of the composite laminates was hindered by the brittle failure of the matrix at low strains. Originality/value These results show that dual extrusion can be used to manufacture multidirectional laminates with tailored mechanical properties in different orientations for various engineering applications.