Microstructure of TRISO coated particles from the AGR-1 experiment: SiC grain size and grain boundary character

作者：Kirchhofer Rita^*; Hunn John D; Demkowicz Paul A; Cole James I; Gorman Brian P

来源：Journal of Nuclear Materials, 2013, 432(1-3): 127-134.

DOI：10.1016/j.jnucmat.2012.08.052

Pre-irradiation SiC microstructures in tristructural-isotropic (TRISO) coated fuel particles from the Advanced Gas Reactor Fuel Development and Qualification program%26apos;s first irradiation experiment (AGR-1) were quantitatively characterized using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). From EBSD, it was determined that only the cubic polymorph of as-deposited SiC was present and the SiC had a high fraction of coincident site lattice (CSL) Sigma 3 grain boundaries. Additionally, the local area misorientation (LAM), which is a qualitative measurement of strain in the SiC lattice, was mapped for each sample fuel variant. The morphology of the SiC/IPyC interfaces were characterized by TEM following site-specific focused ion beam (FIB) specimen preparation. It was determined that the SiC layer had a heavily faulted microstructure typical of chemical vapor deposition (CVD) SiC and that the average grain diameter increased radially from the SiC/IPyC interface for the samples manufactured with similar CVD conditions, while the last sample showed a nearly constant grain size across the layer.

• 出版日期2013-1