Irradiation creep due to climb-induced glide in an anisotropic dislocation structure

Irradiation creep due to the climb-induced glide mechanism in an anisotropic dislocation structure is investigated, at the grain level, using a rate theory approach. The dislocation climb is considered to be affected by a net flow of either interstitials or vacancies to it, as a consequence of the combined effects of the intrinsic and stress-induced (SIPA) biases. In general, strong anisotropy of the creep rate is predicted from the theory, when the effects of the intrinsic and stress-induced biases are comparable. The theory is applied to zirconium. The results show that the creep rate, in general, depends strongly on the orientation of the basal projection of the stress direction in addition to its orientation relative to the $\text{c-}\text{axis}$ for this creep mechanism.