The study of microstructural defects and mechanical properties in proton-irradiated Zr–1.0%Nb–1.0%Sn–0.1%Fe

We had earlier analysed point defects in irradiated Zr–1.0%Nb–1.0% Sn–0.1%Fe samples by positron annihilation lifetime spectroscopy (PALS). The studies revealed the generation of irradiation induced di- and tri-vacancy clusters. In the present work, we have carried out X-ray diffraction line profile analysis (XRDLPA) and studies of mechanical properties like ultimate tensile strength (UTS), yield strength (YS) and percentage elongation (%E) on the same irradiated samples at different doses. XRDLPA reveals that order of dislocation density remains almost unchanged up to the experimental limit of irradiation dose. Attempts have also been made to correlate the changes in mechanical properties with irradiation-induced defects. YS of the alloy increases with irradiation due to locking, or pinning of dislocations with vacancy clusters. However, there is an anomaly in YS at a dose of 5×1020 protons/m2 which has been explained in the light of interaction of vacancies with solute atoms. Percentage elongation on the other hand, shows a monotonic fall with increasing dose.