Amorphization of precipitates in Zr-4 alloy at 310 and 350℃

Proton irradiation at temperatures of 310 and 350 ℃ has been researched using 2 MeV proton to a atom displacement damage level of 5 dpa at a dose rate of 8.5×1013 cm－２·s－１. Amorphization and Fe loss of Zr(Cr,Fe)2 and ZrFe2 precipitates are observed. No amorphization appears in ZrFe2 precipitates at 310 and 350 ℃. Proton irradiation at 350 ℃ does not lead to measurable amorphization or elemental redistribution. An amorphous rim is observed on the surface of Zr(Fe,Cr)2 precipitates, the thickness of which is 5～10 nm, in both a conventional and high-resolution TEM micrograph at 310 ℃. A bright rim is observed in the Fe map, less than 10 nm wide, indicating Fe segregation. Energy-filtered images indicate Fe accumulation in the matrix near the precipitate．