Stability of nano-oxides upon heavy ion irradiation of an ODS material

Owing to their low swelling under irradiation and excellent creep properties, oxide dispersion strengthened (ODS) materials are expected to play an important role as structural components for fusion reactors. These materials are reinforced by a nano-oxide dispersion. Hence, to ensure their good in-reactor mechanical properties, ODS materials have to keep their nano-size precipitates stable under neutron irradiation.The structural stability under irradiation of the oxides is analyzed in a Fe–18Cr–1W–0.3Ti alloy reinforced by 0.5Y2O3 upon high-energy ion irradiations (92-MeV Xe) at room temperature (300 K) and at 780 K up to a fluence of 3 × 1014 cm−2. The use of high-energy heavy ions allows a specific study of the effect of electronic interactions and low ballistic damages on oxides. Results provided by transmission electron microscopy show that the precipitates could exhibit an amorphization after irradiation at room temperature whereas the particles remain crystalline after irritation at 780 K.