Characterisation of irradiation enhanced strain localisation in a zirconium alloy

Abstract

High resolution digital image correlation (HRDIC) has been used to quantify the effect of proton irradiation on strain localisation in Zircaloy-4. Confinement of slip to dislocation channels in irradiated material lead to intense, planar slip bands with high effective shear strain values within channels. More diffuse, homogenous slip was observed in non-irradiated material, with the highest strains measured near grain boundaries. By comparing experimental slip trace angles from HRDIC with theoretical slip trace angles determined using grain orientations from electron backscatter diffraction (EBSD), the active slip plane was determined. Understanding the localised deformation of irradiated materials relative to their microstructure is essential for valid predictions of the structural integrity, and therefore design life, of components in nuclear applications.