Corrosion Science 48 (2006) 3455–3471 www.elsevier.com/locate/corsci 0010-938X/$ - see front matter  2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.corsci.2006.01.005 EVect of iron-containing intermetallic particles on the corrosion behaviour of aluminium Rajan Ambat a,¤ , Alison J. Davenport b , GeoV M. Scamans c , Andreas Afseth d a Department of Manufacturing and Management, Technical University of Denmark, DK 2800 Kgs. Lyngby, Denmark b Metallurgy and Materials, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK c Innoval Technology Limited, Banbury, Oxfordshire, UK d Alcan Technology & Management, CH-8212 Neuhausen, Switzerland Received 21 February 2005; accepted 31 January 2006 Available online 30 March 2006 Abstract The eVect of heat treatment on the corrosion behaviour of binary Al–Fe alloys containing iron at levels between 0.04 and 0.42 wt.% was investigated by electrochemical measurements in both acidic and alkaline chloride solutions. Comparing solution heat-treated and quenched materials with sam- ples that had been subsequently annealed to promote precipitation of Al 3 Fe intermetallic particles, it was found that annealing increases both the cathodic and anodic reactivity. The increased cathodic reactivity is believed to be directly related to the increased available surface area of the iron-contain- ing intermetallic particles acting as preferential sites for oxygen reduction and hydrogen evolution. These particles also act as pit initiation sites. Heat treatment also causes depletion in the solute con- tent of the matrix, increasing its anodic reactivity. When breakdown occurs, crystallographic pits are formed with {1 00} facets, and are observed to contain numerous intermetallic particles. Fine facet- ted Wlaments also radiate out from the periphery of pits. The results demonstrate that the corrosion of aluminium is thus inXuenced by the presence of low levels of iron, which is one of the main impu- rities, and its electrochemical behaviour can be controlled by heat treatment.  2006 Elsevier Ltd. All rights reserved. * Corresponding author. Fax: +45 45 93 62 13. E-mail address: ambat@ipl.dtu.dk (R. Ambat).