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

Proton irradiation at temperatures of 310 and 350 degree C has been researched using 2 MeV proton to a atom displacement damage level of 5 dpa at a dose rate of 8.5 x 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 degree C. Proton irradiation at 350 degree C 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 degree C. 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. (authors)