NSUF 18-1181: In situ TEM observation of microstructural evolution of silicon carbide (SiC)-nanostructured ferritic alloy (NFA) composite under high temperature ion irradiation
Methods: This proposal is to use the Intermediate Voltage Electron Microscopy (IVEM) - Tandem Facility at Argonne National Laboratory to conduct in-situ TEM study of the novel 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites to ion irradiation doses of 0, 10, 20 dpa at 500 and 1000°C in order to understand the irradiation-induced microstructure and defect evolution of the above materials and assess their irradiation tolerance as nuclear cladding materials. Potential impact: Current light water nuclear reactors have potential safety problems due to the rapid reaction between zirconium cladding alloys and water coolant during severe accidents. Development of more accident-tolerant cladding materials becomes a top priority for the future design of nuclear reactors. Nanostructured ferritic alloy (NFA) and silicon carbide (SiC) are two promising cladding materials due to their high thermal stability, good mechanical strength, and strong irradiation and corrosion resistance. SiC-NFA composites are expected to combine the advantages from each component and deliver superior irradiation and accident tolerance. In our work, spark plasma sintered 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites have been demonstrated as promising candidates for nuclear cladding materials. Since both Y-Ti-O particles and SiC-induced secondary phases in the 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites have different size, shape, density, and distribution, in-situ TEM analysis of the microstructural and defect changes under ion irradiation would reveal unknown relationships among different species and their irradiation responses. To avoid any complication introduced by potential changes of the Y-Ti-O particles at 1000°C, the Y-Ti-O particles will be examined/mapped before and after irradiation using energy-filtered transmission electron microscopy (EFTEM), by which the ion irradiation induced high density dislocation loops and the nanoparticles with similar sizes can be differentiated. This proposed effort will help us to establish more quantitative and reliable theoretical models and provide in-depth scientific understanding and performance prediction for these novel systems for fuel cladding applications. The success of this project will also provide guidance for future research and development of high performance fuel cladding materials.
Expected period of performance: The performance period is expected to be November 2017 – October 2018.
Anticipated scientific outcome: The anticipated scientific outcomes include: (1) understanding of the phase stability of the individual phases in the 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites under ion irradiation at different temperatures, (2) in-situ observation of irradiation induced defects and microstructure evolution, (3) quantification of the evolution of the defect type, size, density, and distribution as a function of irradiation dose at high temperatures, (4) synergistic effects of irradiation resistance from the Y-Ti-O clusters and different intermediates and phase boundaries, (5) roles of the reaction barrier layers in the SiC-NFA composites for the irradiation resistance, (6) new theoretical mechanisms/models for fundamental understanding of the irradiation resistance in the SiC-NFA composites, 7) novel cladding materials that are irradiation resistant in the harsh nuclear environments.
Additional Info
| Field | Value |
|---|---|
| Abstract | Methods: This proposal is to use the Intermediate Voltage Electron Microscopy (IVEM) - Tandem Facility at Argonne National Laboratory to conduct in-situ TEM study of the novel 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites to ion irradiation doses of 0, 10, 20 dpa at 500 and 1000°C in order to understand the irradiation-induced microstructure and defect evolution of the above materials and assess their irradiation tolerance as nuclear cladding materials. Potential impact: Current light water nuclear reactors have potential safety problems due to the rapid reaction between zirconium cladding alloys and water coolant during severe accidents. Development of more accident-tolerant cladding materials becomes a top priority for the future design of nuclear reactors. Nanostructured ferritic alloy (NFA) and silicon carbide (SiC) are two promising cladding materials due to their high thermal stability, good mechanical strength, and strong irradiation and corrosion resistance. SiC-NFA composites are expected to combine the advantages from each component and deliver superior irradiation and accident tolerance. In our work, spark plasma sintered 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites have been demonstrated as promising candidates for nuclear cladding materials. Since both Y-Ti-O particles and SiC-induced secondary phases in the 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites have different size, shape, density, and distribution, in-situ TEM analysis of the microstructural and defect changes under ion irradiation would reveal unknown relationships among different species and their irradiation responses. To avoid any complication introduced by potential changes of the Y-Ti-O particles at 1000°C, the Y-Ti-O particles will be examined/mapped before and after irradiation using energy-filtered transmission electron microscopy (EFTEM), by which the ion irradiation induced high density dislocation loops and the nanoparticles with similar sizes can be differentiated. This proposed effort will help us to establish more quantitative and reliable theoretical models and provide in-depth scientific understanding and performance prediction for these novel systems for fuel cladding applications. The success of this project will also provide guidance for future research and development of high performance fuel cladding materials. Expected period of performance: The performance period is expected to be November 2017 – October 2018. Anticipated scientific outcome: The anticipated scientific outcomes include: (1) understanding of the phase stability of the individual phases in the 25 vol% SiC-75 vol% C@NFA and 25 vol% Cr3C2@SiC-75 vol% NFA composites under ion irradiation at different temperatures, (2) in-situ observation of irradiation induced defects and microstructure evolution, (3) quantification of the evolution of the defect type, size, density, and distribution as a function of irradiation dose at high temperatures, (4) synergistic effects of irradiation resistance from the Y-Ti-O clusters and different intermediates and phase boundaries, (5) roles of the reaction barrier layers in the SiC-NFA composites for the irradiation resistance, (6) new theoretical mechanisms/models for fundamental understanding of the irradiation resistance in the SiC-NFA composites, 7) novel cladding materials that are irradiation resistant in the harsh nuclear environments. |
| Award Announced Date | 2018-02-01T14:13:50.79 |
| Awarded Institution | Center for Advanced Energy Studies |
| Facility | Microscopy and Characterization Suite |
| Facility Tech Lead | Alina Zackrone, Wei-Ying Chen, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Kathy Lu |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 1181 |