resumo
In this work the protective effect of layered double hydroxide (LDH) films directly grown on the surface of 2024-T3 aluminium alloy is investigated using electrochemical impedance spectroscopy (EIS) and the scanning vibrating electrode technique (SVET). The SVET results focused on the localised nature of the corrosion process and are in agreement with the global response measured by EIS. Furthermore, the evolution of active corrosion protection rendered by LDH films is surveyed at microscale for the first time for long immersion periods in NaCl solution and in the presence of induced defects. The quantitative information provided by SVET is discussed and a parameter to describe the degree of corrosion localisation is introduced based on LDH systems. (C) 2016 Elsevier Ltd. All rights reserved.
palavras-chave
ALUMINUM-ALLOY 2024-T3; INHIBITION; AL; CHROMATE; COATINGS; METALS
categoria
Electrochemistry
autores
Tedim, J; Bastos, AC; Kallip, S; Zheludkevich, ML; Ferreira, MGS
nossos autores
António Alexandre Cunha Bastos
Investigador Auxiliar
João Tedim
Professor associado
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)
Mikhail Zheludkevich
Investigador Principal Convidado
Silvar Kallip
Investigador Auxiliaragradecimentos
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. JT and SK thank FCT for researcher grants IF/00347/2013 and IF/00856/2013, respectively. Authors also thank FCT (Portugal) for project CONVPROTECT - PTDC/CTM-MAT/1515/2012 and the European Commission for project H2020-MSCA-RISE-2014-645676-MULTISURF. Authors thank Dr. Eddy Domingues for the acquisition of SEM/EDS images.