NSUF 13-410: Characterization and correlation of SiC layer grain size/grain boundary orientation with strength/layer growth conditions - Lite
Silicon carbide (SiC) is a candidate material for a fuel matrix during extended operation of existing light water reactors and as the primary fission product barrier in next generation reactor coated particle fuel. Performance of the SiC layer on particle fuel is a function of factors, including manufacturing parameters and reactor operating conditions. Correlations among these factors and SiC properties may be quantifiable, thereby allowing improved prediction of particle performance based on a few simple measurements rather than extensive characterization. The PIs have previously correlated layer thickness and annealing temperature with the compressive strength and hardness of SiC. The objective of work proposed here is to identify relationships between SiC strength/layer growth conditions (temperature and time) and grain size/grain boundary orientation. The anticipated correlations will link to production parameters and to behavior in various environments. Further, it is expected that these correlations will provide new insight to grain boundary pathways and associated mechanisms of fission product migration through SiC layers. Co-PIs Dr. Isabella van Rooyen at Idaho National Laboratory and Assoc. Professor Mary Lou Dunzik-Gougar (and graduate student) at Idaho State University will analyze SiC coated particle samples already partially characterized at Nelson Mandela Metropolitan University (NMMU), South Africa, and made available for further study in this project. The SiC layers were characterized for compressive strength and hardness (via nano-indentation), the results of which are available for reference in work proposed here. Characterization via Focused Ion Beam (FIB) and Electron Back Scatter Diffraction (EBSD) at the Center for Advanced Energy Studies (CAES) will be used to determine grain size and grain boundary orientations of SiC layers. The PIs anticipated that FIB-EBSD analysis of these small samples with non-standard geometries would require development of a new technique. Through a previous ATR-NSUF Rapid Turnaround Experiment, this new technique was developed and demonstrated by analysis of select samples from the coated particles. As such, successful completion of proposed work is highly probable. The new technique will be used to analyze samples from a larger group differing by production parameters including SiC layer deposition method, time and temperature and annealing time and temperature. It is proposed to analyze 1 or 2 samples, taking up to the maximum allowed 6 days of instrument (FIB) time in 6 months time, which may be conducted over 6 months (January to June 2013). Resulting data will be combined with that from other studies for comparison and to form the basis for an MS thesis to be completed by August 2013. The research potential impact of the overall project is anticipated at many levels. New properties’ and relationships’ data will be developed using a new characterization technique better suited for small, thin and curved SiC samples. Although grain size and orientation of SiC previously have been measured using the EBSD technique, there are no reports of experiments or models correlating those properties with strength and layer growth conditions. Such correlations are anticipated and demonstration will reveal links between bulk mechanical properties and atomic level characterisitics. The experimental data will contribute to model development and improved capability to predict SiC behavior in various conditions and applications. In addition, results of this particular RTE will complete a subset of data that will form the basis for a master’s thesis to be defensed in August of 21013.
Additional Info
| Field | Value |
|---|---|
| Abstract | Silicon carbide (SiC) is a candidate material for a fuel matrix during extended operation of existing light water reactors and as the primary fission product barrier in next generation reactor coated particle fuel. Performance of the SiC layer on particle fuel is a function of factors, including manufacturing parameters and reactor operating conditions. Correlations among these factors and SiC properties may be quantifiable, thereby allowing improved prediction of particle performance based on a few simple measurements rather than extensive characterization. The PIs have previously correlated layer thickness and annealing temperature with the compressive strength and hardness of SiC. The objective of work proposed here is to identify relationships between SiC strength/layer growth conditions (temperature and time) and grain size/grain boundary orientation. The anticipated correlations will link to production parameters and to behavior in various environments. Further, it is expected that these correlations will provide new insight to grain boundary pathways and associated mechanisms of fission product migration through SiC layers. Co-PIs Dr. Isabella van Rooyen at Idaho National Laboratory and Assoc. Professor Mary Lou Dunzik-Gougar (and graduate student) at Idaho State University will analyze SiC coated particle samples already partially characterized at Nelson Mandela Metropolitan University (NMMU), South Africa, and made available for further study in this project. The SiC layers were characterized for compressive strength and hardness (via nano-indentation), the results of which are available for reference in work proposed here. Characterization via Focused Ion Beam (FIB) and Electron Back Scatter Diffraction (EBSD) at the Center for Advanced Energy Studies (CAES) will be used to determine grain size and grain boundary orientations of SiC layers. The PIs anticipated that FIB-EBSD analysis of these small samples with non-standard geometries would require development of a new technique. Through a previous ATR-NSUF Rapid Turnaround Experiment, this new technique was developed and demonstrated by analysis of select samples from the coated particles. As such, successful completion of proposed work is highly probable. The new technique will be used to analyze samples from a larger group differing by production parameters including SiC layer deposition method, time and temperature and annealing time and temperature. It is proposed to analyze 1 or 2 samples, taking up to the maximum allowed 6 days of instrument (FIB) time in 6 months time, which may be conducted over 6 months (January to June 2013). Resulting data will be combined with that from other studies for comparison and to form the basis for an MS thesis to be completed by August 2013. The research potential impact of the overall project is anticipated at many levels. New properties’ and relationships’ data will be developed using a new characterization technique better suited for small, thin and curved SiC samples. Although grain size and orientation of SiC previously have been measured using the EBSD technique, there are no reports of experiments or models correlating those properties with strength and layer growth conditions. Such correlations are anticipated and demonstration will reveal links between bulk mechanical properties and atomic level characterisitics. The experimental data will contribute to model development and improved capability to predict SiC behavior in various conditions and applications. In addition, results of this particular RTE will complete a subset of data that will form the basis for a master’s thesis to be defensed in August of 21013. |
| Award Announced Date | 2013-04-22T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Yaqiao Wu |
| Irradiation Facility | None |
| PI | Mary Lou Dunzik-Gougar |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 410 |