Radiation-stimulated diffusion in Al–Si alloys

Abstract

A di-vacancy low-temperature diffusion is proposed to explain diffusion-controlled processes in Al–Si alloys responsible for neutron-induced silicon precipitation. Ab initio calculations of potential barriers for Si atom hopping in aluminium lattice showed that in the case of di-vacancy diffusion, they are small compared with that of mono-vacancy diffusion. The low temperature diffusivity of mono-vacancies is too small to account for the measured Si diffusivities in aluminium. The dependencies of radiation-stimulated diffusion on the neutron flux and on the temperature are obtained and can be used for the experimental verification of the developed model.

Keywords:

• Neutron-stimulated diffusion
• Di-vacancy diffusion

Acknowledgements

The authors are thankful to Dr. Z. Burshtein for critical reading of the manuscript and Mr. E. Brosh for useful discussions.