Actes du 3ème Colloque International sur la Corrosion et la Protection des Matériaux à Haute Température
J. Phys. IV France 03 (1993) C9-107-C9-113
Influence of the kinetic demixing of cations on ceramic ageing and alloy corrosionC. Petot1, G. Petot-Ervas1, D. Monceau1 and H. Klimczyk2
1 CNRS, LPCM-UPR 211, Université Paris XIII, 93430 Villetaneuse, France
2 Inst. of Metallurgy, Academy of Mining and Metallurgy, Krakow, Poland
This paper concerns the kinetic demixing of cations in semiconducting oxides. From the general equations of matter transport, time-dependent cation redistributions are given for (Co, Mg)O and (Fe, Cr)O solid solutions for which thermodynamical and kinetic data are available. The cation kinetic demixing effects on the reaction rates are described. The conclusions are used to analyse the behavior of (Fe, Cr)O solid solutions under a chemical potential gradient and the effect of Cr on the internal oxidation of Ni-Cr alloys.
© EDP Sciences 1993