Efeitos do tratamento térmico de recozimento na resistência à tração e no alongamento de peças de PLA e PLA HT fabricadas por impressão 3D

Abstract

In the field of engineering, the technological revolution has enabled significant advances in productivity, precision, and sustainability, allowing for the development of new materials as alternatives to traditional manufacturing processes. One such alternative is additive manufacturing (AM), commonly known as 3D printing, which allows for the construction of complex parts in less time and with less waste, standing out due to its versatility. Within AM, fused deposition modeling (FDM) is one of the most widespread methods, enabling the use of biodegradable materials such as polylactic acid (PLA). However, because FDM technology uses a thermoplastic material filament that is heated, extruded, and deposited in layers, its strength is low. This problem can be overcome by using resistance-enhancing mechanisms, such as annealing heat treatment. Thus, this study analyzes the effects produced by annealing heat treatment on the tensile strength and elongation of PLA and PLA HT parts manufactured by 3D printing. With regard to ASTM D638-02a, PLA and PLA HT specimens were manufactured by FDM and subjected to annealing at 70, 100, and 130 °C for 10, 20, and 30 minutes. Subsequently, tensile tests were performed, with data being treated using ANOVA and Tukey's test, in order to identify the influence of material type, temperature, and annealing time on the properties studied. The results indicated that annealing promoted changes in the mechanical properties of PLA and PLA HT, concluding that temperature and material type are factors of significant influence on the tensile strength limit and elongation at break of the analyzed specimens.