Produção de Componentes Metálicos usando uma nova tecnologia de Manufatura Aditiva baseada em Arco de Plasma

• Autor(a) principal: Isidoro, João Francisco
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/21070
• topic: 3DPMD; Eutroloy 16604; Additive Manufacturing; Plasma Transferred Arc; Powder Deposition; Fabricação Aditiva; Arco de Plasma Transferido; Deposição de Pó

Additive manufacturing processes use a wide range of technologies and are increasingly used in several industries, abandoning the stigma that associates them exclusively with the manufacture of prototypes. Due to the advantages presented by this kind of process, such as the absence of moulds and a greater design freedom, additive manufacturing techniques have been incorporated in some industrial sectors. These techniques of additive deposition can be divided into two main categories, namely the Powder Bed System (PBS) and the Direct Energy Deposition (DED). The PBS have been mostly implemented commercially, however present some disadvantages when compared to the DED, such as the limitation of the build volumes, lower production rates and greater difficulty in producing multi-material parts. A new additive manufacturing technique called 3D Plasma Metal Deposition (3DPMD), which is part of the DED techniques, consists in the combination of Plasma Transferred Arc (PTA) welding technology with deposition by means of a robotic arm. This technology has been implemented due to its versatility, being applied for example in industries such as repair and coating of metal parts, or even in the mould industry. In this dissertation, this additive manufacturing process, the 3DPMD, was used as an object of study in the possibility of manufacturing metallic parts, as well as repair processes. In this way, a study of the influence of various parameters of material addition in the process was performed, such as current intensity, speed and deposition rates, and then a qualitative analysis of the material produced was performed. Using a PTA material deposition equipment, combined with a CNC equipment using CAM routines, process parameters were established according to the full factorial Design of Experiments (DoE). Thus, deposited beads were produced with the different parameters and submitted to hardness and geometric analysis tests, to evaluate the optimum process conditions. The ANOVA test allowed concluding the inexistence of correlation between factors, while Spearmen's correlation coefficient allowed knowing the influence of each factor on geometry and hardness. Based on the results obtained, it was possible to produce a piece by adding layers of metallic cord, creating a test cube, which was also submitted to Microhardness tests.