Solid-state phase transitions of two quaternary metallic fuel alloys (U-2.5Mo-2.5Ti-5.0Zr and U-1.5Mo-1.5Ti-7.0Zr in wt. %)

[摘要] This study focuses on the solid-state phase transitions of two quaternary fuel alloys for fast reactors: U-1.5Mo-1.5Ti-7.0Zr (U-MT7Z) and U-2.5Mo-2.5Ti-5.0Zr (U-MT5Z). The characterization techniques are differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). To identify the high temperature phases, the alloys were annealed at 873K, 948K, 1023K, and 1123K (all under 72 hours). Combining those characterizations, the phase transitions are determined. In U-MT7Z, there is one phase transition observed, and it is ascribed to alpha + U2Ti -> gamma transition. In U-MT5Z, two transitions are found. The first transition is alpha -> gamma, while the second is U2Ti -> gamma. The gamma phase onset temperature of U-MT5Z is lower than that of U-MT7Z due to the higher Mo content. (C) 2021 Elsevier B.V. All rights reserved.

[发布日期] 2021-11-01

[关键词] Quaternary uranium alloy;Phase transition;DSC;XRD;SEM/EDS