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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Environmentally friendly sol - gel-based anticorrosive coatings on aluminum alloy 2024

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Author(s):
Giancarlo Richard Salazar-Banda [1] ; Katlin Ivon Barrios Eguiluz [2] ; Artur Jesus Motheo [3] ; Sergio Antonio Spinola Machado [4]
Total Authors: 4
Affiliation:
[1] Universidade Tiradentes. Instituto de Tecnologia e Pesquisa. Programa de Pós-graduação em Engenharia de Processos - Brasil
[2] Universidade Tiradentes. Instituto de Tecnologia e Pesquisa. Programa de Pós-graduação em Engenharia de Processos - Brasil
[3] Universidade de São Paulo. Instituto de Química de São Carlos. Grupo de Eletroquímica Interfacial - Brasil
[4] Universidade de São Paulo. IQSC. Grupo de Materiais Eletroquímicos e Métodos Eletroanalíticos - Brasil
Total Affiliations: 4
Document type: Journal article
Source: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 16, n. 6, p. 1315-1324, 2013-07-23.
Abstract

Chromate coatings used as corrosion protection technologies for aluminum alloys are environmentally harmful and extremely toxic. This paper presents an investigation on the deposition of environmentally friendly cerium oxide-based anticorrosive coatings on aluminum alloy 2024 substrates by the sol - gel method. The influence of the calcination temperature on both the microstructural characteristics and the electrochemical corrosion performance was tested using scanning electron microscopy, X-ray diffraction, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), before and after, periods of immersion in saline corrosive solutions. The ceramic coatings synthesized at 200, 300 and 400 °C showed very resistive behaviors leading to both an efficient passivation of the alloy surfaces and good corrosion protection. This passivation was maintained for 30 days of immersion in saline solutions, as well as, when aggressive electrochemical polarization experiments (until 2.0 V versus saturated calomel electrode) were used. Very high resistances for the charge transfer (0.14-0.28 GΩ) and very low current density values (5 × 10- 14 -5 × 10- 11 A cm- 2) were estimated by EIS and potentiodynamic polarization, respectively, for coatings prepared at 200-400 °C. Thus, the coatings prepared in this study by the sol - gel method appear as an efficient treatment for the corrosion protection of aluminum alloys. (AU)