Artigo de peri??dico
Compreendendo os mecanismos de corros??o de ligas de Al-Cu-Li
On the corrosion mechanisms of Al-Cu-Li alloys: an investigation using global and local electrochemical techniques
Registro en:
0100-4042
6
45
10.21577/0100-4042.20170874
0000-0002-4987-3334
10.4
31
Autor
ARAUJO, JOAO V. de S.
SILVA, REJANE M.P. da
VIVEIROS, BARBARA V.
MILAGRE, MARIANA X.
MACHADO, CARULINE de S.C.
COSTA, ISOLDA
Resumen
In this study, the corrosion mechanism of an Al-Cu-Li alloy manufactured by two different
treatment routes (T3 and T851) was evaluated by immersion and electrochemical tests in solutions containing chloride ions (Cl-). For
both alloys, the formation of cavities on the surface was associated with micrometer-sized intermetallics (IM???s), however, in addition
to this attack, the alloy submitted to T851 treatment also presented an attack called severe localized corrosion (SLC), caused by the
preferential attack to the nanometric T1 (Al2CuLi) phase. The electrochemical concepts involved in these two types of attacks were
discussed. During the IM???s corrosive process, whereas the O2 reduction occurred over the IM???s, the Al dissolution is favored around
the particle, forming trenching and cavities (with 2 and 6 mm of depth). On the other hand, the mechanism associated with the SLC
is related to the formation of a differential aeration cell followed by the evolution of H2, with greater depth of attack penetration
(8 and 35 mm). Additionally, by the use of the Scanning Vibrating Electrode Technique (SVET), it was concluded that the higher
anodic currents observed for the T851 temper were related to the relation between the anodic area (Aa) and the cathodic area (Ac). Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) FAPESP: 19/18388-1; 18/06880-6