Influence of the kinetic demixing of cations on ceramic ageing and alloy corrosion

C. Petot; G. Petot-Ervas; D. Monceau; H. Klimczyk

doi:doi:10.1051/jp4:1993908

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) C9-107-C9-113
DOI: 10.1051/jp4:1993908

Influence of the kinetic demixing of cations on ceramic ageing and alloy corrosion

C. 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

Abstract
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.