Table of Contents
ISRN Materials Science
Volume 2013, Article ID 572379, 5 pages
Research Article

Microstructural and Compositional Characterisation of Chromate Pretreatment on Aluminium

Department of Mechanical Engineering, Landmark University, PMB 1001, Omu-Aran, 251101 Kwara State, Nigeria

Received 7 July 2013; Accepted 19 September 2013

Academic Editors: A. V. Dos Santos and E. Ramous

Copyright © 2013 M. Oki. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Chromate conversion coating developed on aluminium has been examined using SEM/EDX and CTEM/EDX with a view to having further knowledge of its intrinsic surface, plan, and sectional morphologies which will aid the understanding of their roles in improved corrosion and adhesion properties of the underlying substrate. The surface consists of spherical clusters of particulate materials. The sections, however, reveal approximately parallel, linear features which terminate at or close to the metal/coating interface, while plan views show cell-like particulate features. The coating is composed of chromium and aluminium compounds, both, probably hydrated. For a conversion coating to fully replace its chromate counterpart, most of these features may have to be replicated in the nonchromium coating material which should contain nontoxic, leachable corrosion inhibiting species.