Tecnologia em Metalurgia, Materiais e Mineração
https://tecnologiammm.com.br/doi/10.4322/tmm.2011.029
Tecnologia em Metalurgia, Materiais e Mineração
Artigo Original

AN INVESTIGATION ON FRICTION SPOT WELDING IN AA6181-T4 ALLOY

INVESTIGAÇÃO DO PROCESSO DE SOLDAGEM POR FRICÇÃO POR PONTO PARA A LIGA AA6181-T4

Parra, Bruno; Saccon, Vinicius Toledo; Alcântara, Nelson Guedes de; Rosendo, Tonilson; Santos, Jorge Fernandes dos

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Abstract

Friction spot welding is a new solid state welding process, invented and patented by the GKSS Research Centre GmbH in Germany, suitable for spot joining lightweight low melting point materials such as Al and Mg alloys. The process is performed with an especially designed rotating tool (comprised by a clamping ring, sleeve, and pin) that creates a joint between sheets in overlap configuration by means of frictional heat and mechanical work. The result is a spot welded lap joint with minimal material loss and a flat surface with no keyhole. In this work the application of Friction Spot Welding for spot joining the AA6181-T4 is investigated. Different rotational speeds (1900 to 2900 rpm) and welding times (2 to 3.4 s) were tested with the objective of finding the best suited ones for producing high quality joints in terms of microstructure and mechanical performance. Welds with strength in the order of 6.8 kN were obtained with high reproducibility. The results also show that geometric elements of the weld play an important role on the fracture mechanisms and hence on the mechanical performance of the joints. In sum, the results reveal the potential of this process for industrial applications.

Keywords

Friction, Aluminnum, Welding.

Resumo

Soldagem por Ponto por Fricção (SPF) é um novo processo de solda ponto no estado sólido patenteado no Centro de Pesquisas alemão GKSS, que permite se unir pontualmente ligas metálicas com baixo ponto de fusão como as ligas de Al e Mg. O processo é realizado com uma ferramenta especialmente desenvolvida (composta por anel de retenção, camisa e pino) que une as partes em configuração sobreposta por calor de fricção e deformação mecânica. O resultado é uma junta soldada sobreposta com mínima perda de material e superfície lisa sem buracos deixados pela ferramenta. Neste trabalho, é investigado o processo de SPF para a união da liga AA6181-T4. Diferentes velocidades rotacionais (1900 a 2900 rpm) e tempos de soldagem (2 a 3,4 s) foram testados com o objetivo de se encontrar as melhores condições de se produzir juntas de qualidade em termos de microestrutura e desempenho mecânico. Foram obtidas soldas com resistência na ordem de 6,8 kN, com alta reprodutibilidade. Os resultados também mostram que elementos geométricos das juntas têm importante papel nos mecanismos de fratura e, portanto no desempenho mecânico das juntas. Em suma, os resultados revelam potencial do processo para aplicações industriais.

Palavras-chave

Fricção, Alumínio, Soldagem

Referências

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