Abstract
The effects of neutron irradiation on microstructural evolution and the resultant changes in physical and mechanical properties are of critical importance for the development of silicon carbide (SiC) materials for nuclear applications. This study neutron-irradiated β-SiC under a wide range of conditions at temperatures between 235 and 750°C and neutron doses of 0.01–11.8 displacements per atom, and then evaluated the effects on the SiC structure using Raman spectroscopy. The SiC optical phonon lines were shifted to lower wavenumbers by irradiation. Correlations were found among the wavenumber of the longitudinal optical phonon line, irradiation-induced swelling, and irradiation temperature. The peak shift also correlated indirectly with decreasing thermal conductivity of irradiated SiC. The irradiation-induced peak shift is explained by combinations of lattice strain, reduction of the elastic modulus, and other factors including decreasing coherent domain size. These findings bridge irradiation-induced microstructural changes and property changes and illustrate how Raman spectroscopy is a useful tool for nondestructively assessing irradiated SiC materials for nuclear applications.
| Original language | English |
|---|---|
| Pages (from-to) | 1686-1692 |
| Number of pages | 7 |
| Journal | Journal of Raman Spectroscopy |
| Volume | 49 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 2018 |
Funding
*This manuscript has been authored by UT‐Battelle, LLC under Contract No. DE‐AC05‐00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non‐exclusive, paid‐up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy. gov/downloads/doe‐public‐access‐plan). This work was sponsored by the U.S. Department of Energy (DOE), Office of Nuclear Energy, Nuclear Science User Facilities program and the Advanced Fuel Campaign of the Nuclear Technology Research & Development program under contact DE-AC05-00OR22725 with Oak Ridge National Laboratory (ORNL) managed by UT Battelle, LLC. Part of the irradiation was supported by the Office of Fusion Energy Sciences, DOE. A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the ORNL. Jagjit Nanda and Frederick Wiffen (ORNL) provided useful comments on the manuscript.
Keywords
- Swelling
- irradiation defects
- neutron irradiation
- nuclear
- silicon carbide