Anisotropic deformation of Zr ion irradiated Zr–2.5%Nb micro-pillars at 25 °C

Micro-pillars of 5 μm diameter and 5 μm height were made from textured Zr–2.5%Nb pressure tube material and were irradiated with 8.5 MeV Zr+ to simulate neutron irradiation. The yield stress, strain hardening exponent, and degree of strain localization of the micro-pillars when tested at 25 °C increased with ion irradiation and the extent of increase was largest in directions containing low (0 0 0 1) basal pole fraction. This suggests that Zr+ irradiation inhibits prismatic dislocation slip more than pyramidal slip in this material.