EDP Sciences Journals List
Issue J. Phys. IV France
Volume 03, Number C9, Décembre 1993
Proceedings of the 3rd International Symposium on High Temperature Corrosion and Protection of Materials
Actes du 3ème Colloque International sur la Corrosion et la Protection des Matériaux à Haute Température
Page(s) C9-301 - C9-308
DOI http://dx.doi.org/10.1051/jp4:1993929

Proceedings of the 3rd International Symposium on High Temperature Corrosion and Protection of Materials
Actes du 3ème Colloque International sur la Corrosion et la Protection des Matériaux à Haute Température

J. Phys. IV France 03 (1993) C9-301-C9-308

DOI: 10.1051/jp4:1993929

The effect of yttria coatings on the oxidation behaviour of Fe-25Al and Ni-32Al at 1100 and 1200 °C

R. Prescott, D.F. Mitchell, J.W. Fraser and M.J. Graham

Institute for Microstructural Sciences, National Research Council, Ottawa, K1A 0R6, Canada


Abstract
The influence of Y2O3 coatings on the oxidation behaviour of Fe-25wt%Al and Ni-32wt%Al has been investigated at 1100 and 1200 °C. Samples were sputter coated with 4 nm of Y2O3 and oxidized sequentially in 16O2 and 18O2. Oxide scales have been characterized using SIMS, XPS, SEM, X-ray and electron diffraction. A comparison is made between the growth of oxide on Y2O3-coated and uncoated alloys. The major effects of the yttria coating at 1100 °C are to delay the formation of α-Al2O3 and to increase the oxidation rate. At 1200 °C a two-layered scale is formed instead of a single layer; all of the yttrium is contained in a non-adherent outer layer.



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