Process parameter tailored evaluation of FFF-fabricated carbon fibre based poly-lactic-acid composites

Abstract

Fused filament fabrication (FFF) is an Additive manufacturing technique, widely used in engineering that involves adding material layer by layer to create solid objects with complex geometry. Due to the poor mechanical performance of pure thermoplastics materials, one alternative for enhancing the mechanical qualities of FFF created thermoplastic parts is to include reinforcing material, such as carbon fibre (CF). In this work, we perform an FFF analysis of the mechanical behaviour of gyroid infilled CF based poly-lactic-acid (PLA) composites. Tensile behaviour is measured for a variety of parameter combinations, including raster angle (RA) (0°, 45°, 90°), feed rate (FR) (20 mm/s, 40 mm/s, 60 mm/s) and layer height (LH) (0.1 mm, 0.15 mm, 0.2 mm). By adjusting the several process parameters, it is possible to increase tensile strength (TS) by 70.81%, from a minimum of 16.17 MPa to a maximum of 27.62 MPa. The failure mechanisms of the studied specimens are determined using a fractography study, which indicates pulling, necking, raster failure, and voids. Using ANOVA, Taguchi’s L27 array, and regression analysis, the impact of LH, RA, and FR on TS is determined, in which, LH having the highest influence. The results of this study will aid engineers in creating useful components with improved mechanical behaviour.