Abstract
Capillary evolution at bicrystal UO2 grain boundaries is characterized using in situ transmission electron microscopy. The discontinuous nature of the densification process, both particle rotation and axial strain, along with the large activation stress for densification support a hypothesis that grain boundary strain in UO2 follows nucleation rate limited kinetics at low to intermediate stresses, that is, less than (Formula presented.). The temperature dependence of the average activation stress for sintering agrees well with analysis of bulk sintering data and creep data reported within the literature when analyzed in the context of a grain boundary dislocation nucleation rate limited kinetic model.
| Original language | English |
|---|---|
| Pages (from-to) | 6701-6714 |
| Number of pages | 14 |
| Journal | Journal of the American Ceramic Society |
| Volume | 107 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 2024 |
Funding
Work by Shen Dillon and Sarah Finkeldei was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES) under Award # DE‐SC0023447. Work by Andrew Nelson was supported by the Advanced Fuels Campaign of the Nuclear Technology Research and Development program in the Office of Nuclear Energy, US Department of Energy. The authors appreciate discussions about this work with Brent Heuser. Access to the in situ TEM facilities was supported by the US Department of Energy, Office of Nuclear Energy under DOE Idaho Operations Office Contract DE‐AC07‐051D14517 as part of a Nuclear Science User Facilities experiment. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the US DOE's National Nuclear Security Administration under contract DE‐NA‐0003525. The views expressed in the article do not necessarily represent the views of the US DOE or the US Government. This manuscript has been authored by UT‐Battelle, LLC, under contract DE‐AC05‐00OR22725 with the US Department of Energy (DOE). The US Government retains and the publisher, by accepting the article for publication, acknowledges that the US Government retains a nonexclusive, paid‐up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US Government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( https://www.energy.gov/doe‐public‐access‐plan ).
Keywords
- creep
- grain boundaries
- sinter/sintering
- uranium/uranium compounds