Characteristics of creep of fine-grained zirconium

Abstract

Creep studies in the temperature range 300 – 700 K have shown that the deviation from depending the Hall-Petch relationship for a nano-structured zirconium is associated with the decrease of the contribution of the mechanisms of intragranular slip in the plastic deformation and increasing of the contribution of the mechanisms more characteristic of high-temperature creep.
All studied materials have instability of the structural state after creep deformation in the all temperature range. That is a result of the change in the geometry of the applied stress and low strain rate and significantly influences on the creep characteristics.