Microelectrochemical evaluation of severe localized corrosion sites developing on third-generation aluminium alloys
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2021
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CURRENT TRENDS IN ELECTROCHEMISTRY; MEETING OF THE ELECTROCHEMISTY GROUP OF THE SPANISH ROYAL SOCIETY OF CHEMISTRY, 41st; FRENCH‐SPANISH ATELIER/WORKSHOP ON ELECTROCHEMISTRY, 1st
Resumo
Third-generation aluminium-copper-lithium alloys exhibit attractive mechanical properties, in
particular light-weight and significant strength. However, the developed microstructure often
results in severe localized corrosion (SLC) sites with fast in-depth pit propagation
accompanied by H2 evolution.1 Such phenomena stem from a strong galvanic coupling,
mainly established between Fe- and Cu-rich particles and the surrounding matrix. As a result,
strong concentration and pH gradients develop throughout the aluminium surface,
determining the local breakdown of the passive regime eventually provided by aluminium
oxides and corrosion products. Understanding the development of such distributions is key to
outline appropriate strategies for the prevention of fast degradation and materials failure.
Scanning Electrochemical Microscopy (SECM) and Scanning Vibrating Electrode Technique
(SVET) are capable of providing local information on the distribution of active sites and the
presence of reactive chemical species. SVET has previously demonstrated the formation of
gas bubbles ascribed to hydrogen evolution (i.e., electro-reduction process) at the anodically-activated
sites,2,3; whereas local hydrogen production, oxygen consumption and pH changes
are readily accessible using SECM, although with some limitations with regards to the
detection of evolving gas.4
The present contribution reports recent advances in the investigation of local degradation
phenomena occurring at the surface of Al-Cu-Li alloy AA-2098, as bare material and after
friction stir welding. Oxygen consumption over nobler particles acting as cathodic sites, and
SLC accompanied with strong acidification and H2 production at the local anodes were
observed. The determined pH and concentration gradients allow to progress in the knowledge
of the mechanistic aspects involved in the degradation processes on these materials.
Como referenciar
IZQUIERDO, J.; SILVA, R.M.P. da; MILAGRE, M.X.; COSTA, I.; BETANCOR-ABREU, A.M.; SOUTO, R.M. Microelectrochemical evaluation of severe localized corrosion sites developing on third-generation aluminium alloys. In: CURRENT TRENDS IN ELECTROCHEMISTRY; MEETING OF THE ELECTROCHEMISTY GROUP OF THE SPANISH ROYAL SOCIETY OF CHEMISTRY, 41st; FRENCH‐SPANISH ATELIER/WORKSHOP ON ELECTROCHEMISTRY, 1st, July 6-9, 2021, Paris, France. Abstract... p. 89-89. Disponível em: http://repositorio.ipen.br/handle/123456789/32681. Acesso em: 28 Mar 2024.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.