Mechano-Chemical Aspects of High Temperature Oxidation: A Mesoscopic Model Applied to Zirconium Alloys

Abstract

A model is developed in order to study the influence of mechanical aspects during high temperature oxidation of zirconium alloys. This model accounts for oxygen diffusion within the metal and across the oxide scale. Much attention is paid on the role of the Zr–O solid solution on oxidation kinetics and on the role of mechanical anisotropy. The model shows that stresses developed in the metal, due to oxygen dissolution, have a strong influence on oxidation rates. In particular, a change of crystallographic orientation of the metal leads to a change in stress gradients which is responsible for differences in oxidation rates. Such results are confirmed by experimental results.