EVALUATION OF MECHANICAL BEHAVIOUR OF POLYLACTIC ACID (PLA) FABRICATED PARTS VIA FUSED DEPOSITION MODELLING

Abstract

Production of functional parts with additive manufacturing (AM) technologies is a challenging task. Several factors influence their surface finish, dimensional accuracy, mechanical properties and production printing time. The mechanical properties of a built part depend on several process parameters. The effect of infill density, layer thickness and extrusion temperature on the mechanical performance of PLA samples manufactured using a low cost 3D printer was characterized in order to determine the significant configuration parameter that influenced best mechanical properties. Tensile strength, impact strength and hardness test was carried out to determine the mechanical response of the printed specimens. Differences on mechanical response were observed during the physical test of the parts depending on the optimized process parameter. Finite Element Simulation was used to support the experimental test. Due to the layer by layer process, maximum tensile strength of the component produced was achieved at the level of optimized parameter of extrusion temperature of 220°C, 50% infill density and layer thickness of 0.4mm. The significance process parameter to produce higher impact strength was attained at 30% infill density, extrusion temperature of 210°C and layer thickness of 0.2mm, while the infill density of 50%, extrusion temperature of 215°C and layer thickness of 0.3mm exhibited higher values for hardness. Linear multiple regression model was employed to make a numerical prediction of the output characteristics within the range of each process parameter, based on the experimental response obtained for the tensile strength, impact strength and hardness. Finite Element simulation results were in agreement with the experimental results obtained.