___________________________________________________________________________________________ *Corresponding author: Email: makanjuolaoki@justice.com; International Research Journal of Pure & Applied Chemistry 3(2): 147-158, 2013 SCIENCEDOMAIN international www.sciencedomain.org Corrosion of Aluminium in Chloride Environments Makanjuola Oki 1* 1 Department of Chemical Sciences, College of Natural and Applied Sciences, Oduduwa University, Ipetumodu, via Ile-Ife, The State of Osun, Nigeria. Author’s contribution The author MO performed the experiments, interpreted the results and wrote the paper. Received 28 th December 2012 Accepted 29 th March 2013 Published 5 th April 2013 ABSTRACT In order to obtain further insights into the mode of protection afforded by conversion coatings on aluminium substrates, Scanning and Transmission Electron microscopy techniques and potential measurements was employed to monitor variously treated aluminium specimens in chloride environments. Examinations revealed that conversion coated aluminium with top lacquer coatings and subsequently subjected to Chloride environments prevented pitting of the substrate. However, pits were observed on ‘bare’ aluminium and those with top lacquer coatings after being exposed to similar environments. The ‘bare’ chromate coated specimen revealed pits plugged by corrosion products suspected to be hydrated Cr III oxide and/or hydroxide formed through the reduction of Cr VI species present in the coating. Such a capability was not observed for the ‘bare’ chromate-phosphate specimen. Keywords: SEM; TEM; EDX; chromate; pitting corrosion; aluminium. 1. INTRODUCTION As a result of environmental and health considerations, considerable efforts are focussed on formulating conversion coating chemicals devoid of chromates [1-7], however, the restrictions to their use is mostly in the packaging industries. In other applications chromate Research Article