首页|Cr-incorporated uranium nitride composite fuels with enhanced mechanical performance and oxidation resistance

Cr-incorporated uranium nitride composite fuels with enhanced mechanical performance and oxidation resistance

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Cr-incorporated UN (Cr-UN) composite fuels with different Cr amounts up to 10 wt% are fabricated by spark plasma sintering, and their microstructure and phase heterogeneity are analyzed. Highly densified microstructure and homogeneous Cr distribution are identified for the Cr-incorporated UN pellets, demonstrating a liquid sintering characteristic with a Cr enriched phase on the UN grain boundaries. A ternary phase U2CrN3 forms in the Cr-UN matrix with Cr amounts of 5 wt% and 10 wt%. The SPS densified Cr-UN composite pellets display greatly-improved thermal conductivity and simultaneously high hardness and fracture toughness. The fracture toughness of the Cr-incorporated UN pellet is similar to 5.5 MPa-m(1/2), representing almost 130% enhancement as compared to that of monolithic UN sintered at the same condition. The Cr-incorporated UN pellets also display enhanced oxidation resistance as evidenced by increased onset temperature for oxidation to 450 ? for the 5 wt% Cr-UN. These results highlight that Cr additive and the formation of a ternary phase can be useful to improve the thermal-mechanical properties and oxidation resistance of UN fuels with well-maintained high fissile element density. (C)& nbsp;2021 Elsevier B.V. All rights reserved.

Uranium nitrideChromiumMechanical behaviorThermal conductivityOxidationresistanceTEMPERATUREMONONITRIDE

Yang, Kun、Kardoulaki, Erofili、Zhao, Dong、Gong, Bowen、Broussard, Andre、Metzger, Kathryn、White, Joshua T.、Sivack, Michael R.、Mcclellan, Kenneth J.、Lahoda, Edward J.、Lian, Jie

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Rensselaer Polytech Inst

Los Alamos Natl Lab

Westinghouse Elect Co

2022

Journal of Nuclear Materials

Journal of Nuclear Materials

EISCI
ISSN:0022-3115
年,卷(期):2022.559
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