Effect of building orientation and fibre type on the mechanical behaviour of additively manufactured ABS matrix composites

ABSTRACT Additive manufacturing of fibre-reinforced composites show high potential for fabrication of next-generation lightweight complex structural parts. In this study, the effects of building orientation and fibre type, i.e. carbon fibre (CF), and glass fibre (GF), on the mechanical properties of acrylonitrile butadiene styrene (ABS) composites fabricated by fused deposition modelling (FDM) were investigated. The mechanical properties, namely, tensile strength, elastic modulus, hardness, and toughness, were analyzed for flat, on-edge, and upright building orientations. Results revealed that building orientation significantly influences several mechanical properties; in-plane (flat and on-edge) orientations produced the best mechanical properties, whereas upright orientations produced the worst. However, building orientation had little effect on material hardness. Further, compared to the elastic modulus and tensile strength of pure ABS, those of CF-reinforced ABS (CF–ABS) increased by 800% and 500%, respectively, and those of GF-reinforced ABS (GF–ABS) increased by 400% and 400%, respectively, proving that reinforcing ABS with either CF or GF improves the tensile properties. The impact energy of CF–ABS (0.5 J) was lower than that of GF–ABS (1.1 J) because of the brittleness of CF. Fracture surface analysis was performed via scanning electron microscopy (SEM) which gave insight to the nature and mode of fracture of the failed specimens. The most common defects on the printed specimens were void formation, fibre pullout, and poor bonding between fibre and matrix.