Multiscale Electrochemical Study of Welded Al Alloys Joined by Friction Stir Welding

Autor(es)

de Abreu, Caio Palumbo ^{[1, 2]} ; Costa, Isolda ^[1] ; de Melo, Hercilio Gomes ^[3] ; Pebere, Nadine ^[4] ; Tribollet, Bernard ^[2] ; Vivier, Vincent ^[2]

Afiliação do(s) autor(es)

^[1] Ctr Ciencia & Tecnol Mat, Inst Pesquisas Energet & Nucl, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Paris 06, CNRS, Lab Interfaces & Syst Electrochim, UPR 15, CP 133, F-75252 Paris 05 - France

^[3] Univ Sao Paulo, Dept Eng Met & Mat, BR-05508030 Sao Paulo, SP - Brazil

^[4] Univ Toulouse, CIRIMAT, CNRS, UPS, INPT, ENSIACET, BP 44362, F-31432 Toulouse 04 - France

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Electrochemical Society; v. 164, n. 13, p. C735-C746, 2017.
• Citações Web of Science: 2

Resumo

Friction stir welding (FSW) is an efficient way to join high strength aluminum alloys. However, FSW generates different microstructural areas in contact that may give rise to galvanic couplings, affecting the corrosion resistance of the assembly. In the present work, a multiscale electrochemical study of the 7475-T651 and 2024-T3 aluminum alloys butt-joined by FSW was carried out. Much lower impedances were associated with the FSW affected zones compared to the two aluminum base metals tested individually. Corrosion of the welded system resulted in the establishment of galvanic coupling, shown by local electrochemical impedance spectroscopy (LEIS) measurements, at which the AA7475 behaves anodically with respect to the AA2024. A Zn deposit was observed on the intermetallic particles of the AA2024 after 24 h of immersion in the electrolyte resulting from the galvanic coupling, which seems to reduce the galvanic coupling effects. Such a behavior in combination with LEIS results allowed a description of the galvanic coupling development between two different aluminum alloys (AA2024-T3 and AA7475-T761) butt-welded by FSW as a function of time from the early stage of immersion. (c) 2017 The Electrochemical Society. All rights reserved. (AU)

• Processo FAPESP: 13/13235-6 - Estudo da corrosão localizada e caracterização da resistência à corrosão associada à fadiga na região de solda em ligas de alumínio de elevada resistência soldadas por fricção (FSW)
• Beneficiário: Isolda Costa
• Modalidade de apoio: Auxílio à Pesquisa - Temático