Competing influence of vacancies and interstitial atoms on temperature dependence of creep under irradiation

ABSTRACT In the framework of the Orowan model, a theoretical approach is developed to explain the appearance of a break (local minimum and maximum) on a curve of creep rate dependence on temperature of materials under irradiation. The break is explained by competition of radiation and thermal defect fluxes to dislocations. At some temperature, the fluxes of interstitial atoms and vacancies become equal and compensate each other. Thus, the dislocations do not climb. Climb–glide mechanism does not contribute to the creep and the creep decreases. It is shown that the presence of sinks with different preference coefficients is necessary for the appearance of the break. Theoretical and experimental results are in good agreement.