Scanning Auger electron spectroscopy study of the oxide film formed on dendritic and interdendritic regions of C containing Fe 3 Al intermetallic V. Shankar Rao a , M. Norell b , V.S. Raja a, * a Corrosion Science and Engineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India b Department of Materials Science and Engineering, Chalmers University of Technology, SE-412 96 G€ oteborg, Sweden Abstract The oxide films formed during early stage of oxidation at 800 °C on dendritic and inter- dendritic regions of the cast Fe–16Al–1C (wt.%) alloy were studied using scanning Auger electron spectroscopy. Microhardness measurement and elemental depth profiles by Auger spectroscopy reveal that the carbide, Fe 3 AlC 0:69 , is the major constituent of the interdendritic region, while dendrites are predominantly Fe 3 Al phase. Between the two, the interdendritic region is found to be more prone to oxidation than the dendritic region, which was attributed to presence of carbides with low-Al content. In spite of the difference in oxide film thickness exhibited by both the phases, they consist of an inner aluminium oxide layer and an outer iron oxide layer. Keywords: Intermetallics-iron aluminide; AES; XRD; Interfaces; Oxidation 1. Introduction In recent years, there has been increasing number of studies on the development of carbon containing iron aluminides, for high temperature applications [1–5]. This is