Influência do desbalanceamento da onda retangular na liga de alumínio 6063-T6 soldada pelo processo TIG-CA

• Ano de defesa: 2015
• Autor(a) principal: Catarino, Jonny Max [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Soldagem; Aluminio; Ligas de aluminio; Welding
• Link de acesso: http://hdl.handle.net/11449/132497; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/15-12-2015/000853552.pdf

The weldability of the aluminum alloys is highly influenced by the weld current nature; it could interfere significantly on the desirable quality. The use of alternated current on the TiG welding processes, promote innumerous possibilities like, flexibilities on the change the wave frequency, positive current amplitude as the negative current amplitude, furthermore the actuations time of positive and negative polarity of electrode in the same wave cycle. The selected configuration has the important effect on the final properties on the weld bead. The use of alternated current on the aluminum alloys welding are largely used and has the finally, to promote the superficial oxide layer cleaning Al2O3, in the same time that it promote the weld penetration. On the literature is very common to find the affirmatives where the oxide layer cleaning of Al2O3 on the welding is linked on the positive time on the wave cycle, and the penetration is linked at the negative time for the same wave cycle. For this proposal research was realized the TIG-CA welding on the AA 6063-T6 aluminum alloys, by a bead-on-plate with the square wave, induced by weld current variations as the acting time of positive polarity of the electrode on the wave cycle. The weld current applied were 100 A, 120 A and 140 A. The initial conditions utilized was a balanced on 50% of acting time of positive polarity in the wave period in a 20 ms, followed by a unbalance of 32,5% and 15% of the actuation time of positive polarity in the electrode, keeping the unaltered frequency on 50 Hz for all configurations. Was observed that the unbalanced wave interfere direct on the final result of weld bead. The results for the selected configurations shows that decreasing the actuations time of electrode positive polarity on the wave cycle promote the reducations of death and wide on the weld bead. The obtained micrographia for a different actuations time of positive polarity shows that the...