PRELIMINARY MODEL OF RADIATION-DAMAGE IN CERAMICS

A preliminary model of radiation damage in binary ceramic oxides has been developed. The model described here accounts in an approximate way for some of the major differences between metallic alloys and ceramics that are believed to be responsible for the fact that ceramic materials appear in some cases to behave differently than metallic alloys when exposed to displacive irradiation. The model considers the influence of the existence of a second lattice and the additional constraint of stoichiometric point defects absorption by dislocation loops on the concentrations of point defects that would be observed at steady state in an irradiated ceramic. These point defect concentrations are then used to compute various measures of the sensitivity of these materials to the type of microstructural evolution that is observed in irradiated metals. Initial results indicate that both the lattice and stoichiometry effects can help to mitigate radiation damage in ceramics. However, the effect is not necessarily large. In agreement with recent data, the results indicate that at least some ceramic oxides may exhibit a sensitivity to displacement damage that is similar to metals. Copyright © 1990, Wiley Blackwell. All rights reserved