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Publicação
ANÁLISE DA ESTABILIDADE DO PROCESSO DE FABRICO ADITIVO POR ARCO SUBMERSO UTILIZANDO UM OSCILOSCÓPIO DIGITAL
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Orientador(es)
Resumo(s)
O Fabrico Aditivo por Arco Submerso (SAAM) é uma tecnologia emergente do Fabrico
Aditivo por Arco com Fio (WAAM) reconhecida pela sua alta taxa de deposição e produtividade superior em comparação com outros processos WAAM. Esta tese examina a estabilidade
e ajuste do processo SAAM no modo AC (Alternating Current) para o fabrico de estruturas de
parede única de aço de baixo carbono. Várias combinações de frequência e equilíbrio AC foram exploradas para avaliar a estabilidade do arco durante a deposição, a consistência geométrica das estruturas e a homogeneidade microestrutural e mecânica das peças depositadas.
Este estudo recorreu à monitorização em tempo real com um osciloscópio digital, se-
guida de uma análise detalhada dos sinais registados, para estabelecer relações entre processo,
estrutura e propriedades. Além disso, foram fabricadas paredes bimetálicas de aço inoxidável
e aço de baixo carbono, com o objetivo de alcançar maior produtividade através da otimização
dos parâmetros de equilíbrio AC e frequência. Os resultados demonstram que o ajuste controlado da frequência e do equilíbrio AC é essencial para minimizar defeitos como a porosidade,
melhorar a estabilidade geométrica, reduzir instabilidades do processo e aumentar a produtividade global. Os resultados variaram entre falta de fusão e as mais elevadas taxas de deposição possíveis, dependendo das configurações de AC, enquanto a corrente, a tensão e a velocidade de avanço se mantiveram constantes, o que evidencia a influência significativa dos parâmetros de AC estudados neste trabalho.
Submerged Arc Additive Manufacturing (SAAM) is an emerging Wire Arc Additive Manufacturing (WAAM) technology recognized for its high deposition rate and superior productivity compared to other WAAM processes. This thesis examines the stability and suitability of the SAAM process in alternating current (AC) mode for fabricating single-wall structures of low-carbon steel. Various combinations of AC frequency and AC balance were explored to evaluate arc stability during deposition, geometrical consistency of the structures, and microstructural and mechanical homogeneity of the deposited parts. The study employed real-time monitoring using a digital oscilloscope, followed by detailed analysis of the recorded signals, to establish process–structure–property relationships. Furthermore, bimetallic walls of stainless steel and low-carbon steel were fabricated with the aim of achieving higher productivity through optimized AC balance and AC frequency pa- rameters. The findings demonstrate that controlled adjustment of AC frequency and AC balance is essential to minimize defects such as porosity, enhance geometrical stability, reduce process-related instabilities, and improve overall productivity. Outcomes ranged from lack of fusion to the highest achievable deposition rates depending on the AC settings, while current, voltage, and travel speed were kept constant, which highlights the significant influence of AC parameters studied in this work.
Submerged Arc Additive Manufacturing (SAAM) is an emerging Wire Arc Additive Manufacturing (WAAM) technology recognized for its high deposition rate and superior productivity compared to other WAAM processes. This thesis examines the stability and suitability of the SAAM process in alternating current (AC) mode for fabricating single-wall structures of low-carbon steel. Various combinations of AC frequency and AC balance were explored to evaluate arc stability during deposition, geometrical consistency of the structures, and microstructural and mechanical homogeneity of the deposited parts. The study employed real-time monitoring using a digital oscilloscope, followed by detailed analysis of the recorded signals, to establish process–structure–property relationships. Furthermore, bimetallic walls of stainless steel and low-carbon steel were fabricated with the aim of achieving higher productivity through optimized AC balance and AC frequency pa- rameters. The findings demonstrate that controlled adjustment of AC frequency and AC balance is essential to minimize defects such as porosity, enhance geometrical stability, reduce process-related instabilities, and improve overall productivity. Outcomes ranged from lack of fusion to the highest achievable deposition rates depending on the AC settings, while current, voltage, and travel speed were kept constant, which highlights the significant influence of AC parameters studied in this work.
Descrição
Palavras-chave
SAAM WAAM SEM Parâmetros Geometria Microestrutura