Abstracts and Available Papers Presented at the
2000 International RERTR Meeting

A Theoretical Model for the Irradiation-Enhanced Interdiffusion of Al and U Alloys

J. Rest,
 Argonne National Laboratory,
 9700 S. Cass Ave.,
 Argonne, IL 60439, USA

Abstract

A model for the interdiffusion of Al and U alloys has been developed based on the premise that the generation of a high dislocation density leading to the formation of a cellular dislocation network provides a sufficient sink density in the material such that the sinks dominate defect behavior. The theoretical model thus derived has the following characteristics: 1. The effective interdiffusion coefficient is proportional to fission rate to the 3/4 power and exponentially dependent on temperature, 2. The interstitial migration enthalpy is given by e_i-e_v/2 =0.74eV , and 3. The model is consistent with uranium-silicide interdiffusion data if the vacancy migration enthalpy is »0.5eV. Finally, it is shown that the lack of SEM-resolvable bubbles in uranium aluminide is consistent with item 2, above, i.e.,e_i-e_v/2 > 0.

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