Microstructure Evolution in U-10Zr Alloy Irradiated by Swift Xe Ions at 700∘C

Abstract The post-irradiation examination (PIE) results of U-10Zr binary metallic fuel that was irradiated by 84 MeV Xe ions at 700∘C are reported. The U-10Zr specimen was synthesized by homogenizing elemental U and Zr powders through arc-melting. The as-fabricated U-10Zr was dominated by the sub-micron acicular α + δ phase. After being irradiated by 84 MeV Xe ions at 700∘C up to 2.19 × 1017 ions/cm2 fluence, the U-10Zr was speculated to evolve into micro-scale γ 1 + γ 2 phases as predicted by the U-Zr phase diagram. During post-irradiation cooling, the U-rich γ1 phase was mainly transformed to the α phase, while the Zr-rich γ2 phase was partially retained along with formation of hexagonal structure phase (δ or ω). Xe bubbles formed in the γ1 and γ2 phases have salient different morphologies, implying faster Xe diffusion in the γ1 phase than the γ2 phase. The quantitative bubble morphology data collected in this study can provide valuable references for the development and validation of fuel performance models for this fuel.