Interdiffusion Behavior of U3Si2 with FeCrAl via Diffusion Couple Studies (vol 502, pg 356, 2018)

[摘要] Uranium silicide (U3Si2) is a candidate to replace uranium oxide (UO2) as light water reactor (LWR) fuel because of its higher thermal conductivity and higher fissile density relative to the current standard, UO2. A class of Fe, Cr, Al alloys collectively known as FeCrAl alloys that have superior mechanical and oxidation resistance are being considered as an alternative to the standard Zirconium based LWR cladding. The interdiffusion behavior between FeCrAl and U3Si2 is investigated in this study. Commercially available FeCrAl, along with U3Si2 pellets were placed in diffusion couples. Individual tests were performed at temperatures ranging from 500 degrees C to 1000 degrees C for 30 hours and 100 hours. The interdiffusion was analyzed with an optical microscope, scanning electron microscope, and transmission electron microscope. Uniform and planar interdiffusion layers along the material interface were illustrated with backscatter electron micrographs and energy-dispersive X-ray spectroscopy. Electron diffraction was used to validate phases present in the system, including distinct U2Fe3Si/UFe2 and UFeSi layers at the material interface. While no interaction was observed at 500 degrees C, interaction was observed at and above 600 degrees C. The amount of interaction between the two materials enhanced progressively at elevated temperatures. (C) 2018 Published by Elsevier B.V.

[发布日期] 2018-08-15

[关键词] U3Si2;FeCrAl;Cladding