Elaboration and microstructural characterization of calcareous/ceria based composite on zinc substrate
- Authors: Aiouaz F.1,2, Jeannin M.2, Creus J.2, Saidani B.3
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Affiliations:
- Laboratoire d’Electrochimie et Corrosion
- Laboratoire des Sciences de l’Ingénieur pour l’Environnement (LaSIE—UMR 7356 CNRS)
- Laboratoire d’Electrochimie, Corrosion et de Valorisation Energétique (LECVE), Faculté de Technologie
- Issue: Vol 52, No 5 (2016)
- Pages: 894-899
- Section: New Substances, Materials, and Coatings
- URL: https://journal-vniispk.ru/2070-2051/article/view/203425
- DOI: https://doi.org/10.1134/S2070205116050026
- ID: 203425
Cite item
Abstract
Cerium conversion coatings were prepared by cathodic electrodeposition from a low concentrated aqueous solution of Ce(NO3)3 with KNO3 addition to insure the conductivity of the electrolyte. The cerium oxide film was characterized by Scanning Electronic Microscopy (SEM). Although the deposit is uniform with current density of 2 mA/cm2, it shows cauliflower morphology with a crack network, giving rise to bad mechanical and electrochemical behaviour. Elaboration of a calcareous deposit inside crack network of the cerium coating by cathodic polarization from artificial seawater is investigated at different applied potential, in order to increase the quality of the cerium coating formed. For cathodic potentials lower than–1.5 V/SCE, zinc corrosion products (gordaite) were observed inside the cerium oxide film instead of calcareous deposit although the current density decrease during the deposition suggesting a partially blocked surface. A pure calcareous compound was observed at–1.5 and–1.6 V/SCE. SEM and EDX cartography of the cross section revealed that open cracks in the cerium oxide structure are filled by calcium. Calcium was also detected inside the CeO2 film not only all around the cracks but also in all the porosity of the CeO2 film. It has precipitated as CaCO3 (aragonite form) as revealed by micro-Raman spectroscopy and XRD.
About the authors
F. Aiouaz
Laboratoire d’Electrochimie et Corrosion; Laboratoire des Sciences de l’Ingénieur pour l’Environnement (LaSIE—UMR 7356 CNRS)
Email: marc.jeannin@univ-lr.fr
Algeria, Bordj El Bahri, Alger; Avenue Michel Crépeau, La Rochelle Cedex 1, 17042
M. Jeannin
Laboratoire des Sciences de l’Ingénieur pour l’Environnement (LaSIE—UMR 7356 CNRS)
Author for correspondence.
Email: marc.jeannin@univ-lr.fr
France, Avenue Michel Crépeau, La Rochelle Cedex 1, 17042
J. Creus
Laboratoire des Sciences de l’Ingénieur pour l’Environnement (LaSIE—UMR 7356 CNRS)
Email: marc.jeannin@univ-lr.fr
France, Avenue Michel Crépeau, La Rochelle Cedex 1, 17042
B. Saidani
Laboratoire d’Electrochimie, Corrosion et de Valorisation Energétique (LECVE), Faculté de Technologie
Email: marc.jeannin@univ-lr.fr
Algeria, Bejaia, 06000
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