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Authors
Abstract(s)
O Fabrico Aditivo apresenta-se, desde o ano de 2012, como o principal plano
estratégico e operacional da Marinha dos EUA para acompanhar a evolução e revolução
da tecnologia mundial, através do aumento e do aprimoramento dos equipamentos. Sendo
assim, e por forma a evoluir na produção e disponibilização de equipamentos necessários
ao cumprimento das missões atribuídas à esquadra, considera-se fulcral a aderência da
Marinha Portuguesa à tecnologia do Fabrico Aditivo. Foi em novembro de 2021, através
de um despacho do Comando Naval, que a Marinha Portuguesa manifestou propensões
na implementação do Fabrico Aditivo a bordo das Unidades Navais, tendo como principal
propósito a mitigação das dificuldades sentidas por parte da cadeia de abastecimento.
A aplicabilidade da utilização de ligas de aço revestida com fluxo rutílico a bordo dos
Navios da Classe Viana do Castelo, quando usado o WAAM (Wire Arc Additive
Manufacturing), foi verificada e caracterizada como concebível, não só por se ter
verificado a possibilidade de construção e de redução da quantidade de gás de proteção
empregue no processo, sem o comprometer, como também pela ausência de inclusões no
material, devido à presença de óxido de titânio no fluxo. Através da análise das inúmeras
condições de deposição em estudo obter-se-á a condição de parâmetros ideal recorrendo
a um otimizador de resposta pelo método “design of experiments”, isto é, planeamento de
experiências, que requer a seleção da maximização ou minimização das variáveis de
resposta, isto é, energia do arco, ondulação, altura por camada, largura e penetração. A
realização de ensaios mecânicos, nomeadamente os ensaios de tração, permitiu verificar
a existência do fenómeno de anisotropia, onde os elevados valores de ductilidade e
deformação se mostraram relevantes nos provetes horizontais. No que diz respeito à
microestrutura, nomeadamente à avaliação da microdureza e dos constituintes presentes
na parede de soldadura, verificou-se que esta apresentava níveis de microdureza
relativamente baixos e grãos refinados de tamanho reduzido.
Since 2012, Additive Manufacturing has been the main strategic and operational plan of the US Navy, to keep up with the evolution and revolution of world technology, through the increase and improvement of equipment. Therefore, and in order to evolve in the production and availability of equipment necessary for the fulfilment of the missions assigned to the fleet, the Portuguese Navy's adherence to Additive Manufacturing technology is considered essential. It was in November 2021, through an order from the Naval Command, that the Portuguese Navy expressed its propensity to implement Additive Manufacturing on board Naval Units, with the main purpose of mitigating the difficulties experienced by the supply chain. The applicability of the use of steel alloys coated with rutile flux on board Viana do Castelo Class Ships, when using WAAM (Wire Arc Additive Manufacturing), was verified and characterized as conceivable, not only for having verified the possibility of building and reducing the amount of shielding gas employed in the process, without compromising it, but also for the absence of inclusions in the material, due to the presence of titanium oxide in the flux. Through the analysis of the numerous deposition conditions under study, the ideal parameter condition will be obtained using a response optimizer using the "design of experiments" method, that is, experiment planning, which requires the selection of the maximization or minimization of the response variables, ie, arc energy, ripple, thickness per layer, width, and penetration. The performance of mechanical tests, namely the tensile tests, made it possible to verify the existence of the anisotropy phenomenon, where the high values of ductility and deformation proved to be relevant in the horizontal specimens. Regarding the microstructure, namely the evaluation of the microhardness and the constituents present in the weld wall, it was found that it had relatively low levels of microhardness and refined grains of reduced size.
Since 2012, Additive Manufacturing has been the main strategic and operational plan of the US Navy, to keep up with the evolution and revolution of world technology, through the increase and improvement of equipment. Therefore, and in order to evolve in the production and availability of equipment necessary for the fulfilment of the missions assigned to the fleet, the Portuguese Navy's adherence to Additive Manufacturing technology is considered essential. It was in November 2021, through an order from the Naval Command, that the Portuguese Navy expressed its propensity to implement Additive Manufacturing on board Naval Units, with the main purpose of mitigating the difficulties experienced by the supply chain. The applicability of the use of steel alloys coated with rutile flux on board Viana do Castelo Class Ships, when using WAAM (Wire Arc Additive Manufacturing), was verified and characterized as conceivable, not only for having verified the possibility of building and reducing the amount of shielding gas employed in the process, without compromising it, but also for the absence of inclusions in the material, due to the presence of titanium oxide in the flux. Through the analysis of the numerous deposition conditions under study, the ideal parameter condition will be obtained using a response optimizer using the "design of experiments" method, that is, experiment planning, which requires the selection of the maximization or minimization of the response variables, ie, arc energy, ripple, thickness per layer, width, and penetration. The performance of mechanical tests, namely the tensile tests, made it possible to verify the existence of the anisotropy phenomenon, where the high values of ductility and deformation proved to be relevant in the horizontal specimens. Regarding the microstructure, namely the evaluation of the microhardness and the constituents present in the weld wall, it was found that it had relatively low levels of microhardness and refined grains of reduced size.
Description
Keywords
Marinha Portuguesa Fabrico Aditivo Otimizador Ensaios Mecânicos Microestrutura