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
The effect of yttria coatings on the oxidation behaviour of Fe-25Al and Ni-32Al at 1100 and 1200 °CR. Prescott, D.F. Mitchell, J.W. Fraser and M.J. Graham
Institute for Microstructural Sciences, National Research Council, Ottawa, K1A 0R6, Canada
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.
© EDP Sciences 1993