Environmentally Friendly Sol-gel-based Anticorrosive Coatings on Aluminum Alloy 2024

Autor(es)

Salazar-Banda, Giancarlo Richard ; Barrios Eguiluz, Katlin Ivon ; Motheo, Artur Jesus ; Spinola Machado, Sergio Antonio

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 16, n. 6, p. 10-pg., 2013-11-01.

Resumo

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 degrees 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 G Omega) and very low current density values (5 x 10(-14) -5 x 10(-11) A cm(-2)) were estimated by EIS and potentiodynamic polarization, respectively, for coatings prepared at 200-400 degrees 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)

• Processo FAPESP: 06/50692-2 - O uso do metodo sol-gel para a producao de recobrimentos de sio2 e/ou ceo2 sobre ligas de aluminio utilizadas na industria aeronautica para a protecao contra a corrosao.
• Beneficiário: Giancarlo Richard Salazar Banda
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado