Materials Science Forum, Vol.408-4, 999-1006, 2002
Texture effects on zircaloy oxidation: Experiment and simulation
The aim of our work is to study the role of mechanical stresses on the oxidation of zirconium and its alloys. For this study, we first emphasize experimentally an effect of the metal texture on the oxidation kinetics as well oxide texture. An experimental determination of the texture of zircaloy is undertaken using an area detector. Two types of metal texture are chosen ({100} and {001}). After oxidation, ODF of zirconium oxide (ZrO2 monoclinic) are calculated using a direct method (WIMV). Two kinds of preferred orientation of the oxide are revealed : one which is related to the epitaxial relationships between Zr and ZrO2 and the other one which is induced by the grain growth in the oxide scale during oxidation process. Evolution of oxide texture is then discussed as a function of metal anisotropy. At the same time oxide growth is measured "in-situ" using thermogravimetric methods. It shows the texture-corrosion rate relation during zirconium oxidation. These experimental results will be compared to theoretical studies. The simulations are performed with a finite element method by using a mechano-chemical model taking into account the anisotropy and the properties gradients of the specimen. It allows the calculation of zirconium oxide growth.