Irradiation-induced hardening of Zircaloy-2 at room temperature under external stress conditions

The irradiation-induced hardening behavior of Zircaloy-2 under irradiation with 3.2 MeV Ni³⁺ ions at room temperature (RT) with stress conditions was investigated using transmission electron microscope (TEM) examination and nanoindentation measurements. The results indicated that the impact of external tensile stress on the hardening of unirradiated samples was not significant. Although stress-induced dislocation lines were observed in samples stressed above 450 MPa, they were unevenly distributed and not dense enough to cause significant changes in hardness. Samples subjected to 1 dpa irradiation under stress exhibited a noticeable increase in hardness, but the extent of hardening remained nearly unchanged across different stress levels, suggesting a minor influence of external tensile stress. This study offers insights into the irradiation-induced hardening behavior of Zircaloy-2 subjected to a 1 dpa irradiation under the influence of external stress conditions at room temperature.