Corrosion behaviour of sediment electro-codeposited Ni-Al2O3 composite coatings

Date

2014

Advisors

Journal Title

Journal ISSN

ISSN

Volume Title

Publisher

Elsevier

Type

Article

Peer reviewed

Yes

Abstract

NieAl 2O3 composite coatings were produced by the sediment electro-codeposition (SECD) technique at various particle loadings and current densities. The submicron Al 2O3 particles were found to distribute uniformly in the coating, and 12e18 vol.% particles can be incorporated in the coating depending on deposition current density and particle loading in the plating bath. Electrochemical corrosion testing was conducted in 0.9 wt.% NaCl solution. The results show that the incorporation of Al 2O3 particles in the coating did not affect the general corrosion behaviour of the Ni coating. However, at higher anodic potentials approaching the breakdown potential and with prolonged polarization, the composite coatings showed deteriorated corrosion resistance in terms of increased anodic current density, reduced pitting potential and quicker breakdown of the passivefilm. The detrimental effects of Al 2O3 particle incorporation could be explained by the existence of numerous boundaries between the particles and the matrix, which would serve as active sites for anodic dissolution and micro-pit formation.

Description

Keywords

corrosion, coatings, composite materials, electrochemical properties

Citation

Sun, Y., Flis-Kabulska, I. and Flis, J. (2014) Corrosion behaviour of sediment electro-codeposited Ni-Al2O3 composite coatings. Materials Chemistry and Physics, 145 (3), pp. 476-483.

Rights

Research Institute

Institute of Engineering Sciences (IES)