Irradiation induced microstructural changes in Zr-Excel alloy

The in situ ion irradiation technique has been employed to elucidate irradiation damage in the dual phase Zr-Excel alloy. 1 MeV Kr ion irradiation experiments were conducted at different temperatures ranging from 100 °C to 400 °C. Damage microstructures have been characterized by transmission electron microscopy in both the alpha (α) and beta (β) phases after a maximum dose of 10 dpa at different temperatures. Several important observations including low temperature 〈c〉-component loop formation, and irradiation induced omega (ω) phase precipitation have been reported. In situ irradiation provided an opportunity to observe the nucleation and growth of basal plane 〈c〉-component loops and irradiation induced dissolution of secondary phase precipitates at the same time. It has been shown that under Kr ion irradiation the 〈c〉-component loops start to nucleate and grow above a threshold dose, as has been observed for neutron irradiation. Furthermore, the role of temperature, material composition and pre-irradiation microstructure has been discussed in detail.