Impacto da potência e da velocidade de varredura do laser na fabricação de estruturas de suporte em aço inoxidável 316L via fusão em leito de pó

Abstract

Additive Manufacturing (AM), also known as 3D printing, emerges as a set of manufacturing techniques challenging conventional production limitations and revolutionizing the way parts for various industrial sectors are designed and conceived. Among the various categories of AM, Laser Powder Bed Fusion (L-PBF) focusing on metals stands out, paving the way for the execution of part designs with previously considered unfeasible geometries. Despite offering several advantages, overhang surfaces require the use of support structures. These structures aim to assist heat dissipation, provide dimensional stability, and reduce residual stresses generated in the part during processing. Although their role in the success of L-PBF manufacturing is acknowledged by the scientific community, support structures have remained relatively underexplored in the literature. In this context, the present work investigated the impact of processing parameters, specifically laser power (Č) and scanning speed (Ĭ), on the dimensioning and tensile strength of non-solid block-type support structures manufactured in AISI 316L stainless steel. Studying how scanning speed and laser power influence support structures is crucial since combining appropriate parameters can increase manufacturing productivity, reduce risks and costs, mitigate warping of the manufactured part, and ensure that the design of support structures is properly replicated throughout L-PBF manufacturing. The presented method is divided into three stages: (1) exploratory, (2) mechanical characterization, and (3) analysis. The results indicate that support structures become more robust and resistant as Č levels increase. On the other hand, the opposite effect is observed with an increase of Ĭ. In addition, defects were detected at the interfaces between the bulk and support regions, which were crucial for the failure of the tensile test specimens. For a layer thickness corresponding to 60 µm, it was verified that the combination of Č and Ĭ which resulted in the highest tensile resistance was 350 W and 1300 mm/s, respectively.