NSUF 23-1905: Electron tomography study of dislocation loops and precipitates in ion irradiated Fe-Cr alloys
This proposal aims to examine the 3D configuration of petal-shaped dislocation loops and heterogeneously distributed precipitates in ion-irradiated Fe-Cr model alloys. Ferritic-martensitic (FM) steels are promising candidates for the structural components in Generation IV fission reactors (such as liquid metal fast reactors and molten salt reactors) due to high temperature performance, good swelling and corrosion resistance. At specific material service temperatures, the formation of dislocation loops and irradiation-induced precipitations in irradiated FM steels can significantly influence the material properties. Our recent TEM studies have observed intriguing petal-shaped loops and precipitate denuded zones near carbides and dislocations in Fe-Cr model alloys. However, conventional 2D-projection TEM images are insufficient to understand the relationship between the 3D structures of these features. In this proposal, we pursue further electron tomography study to explore the 3D distribution and formation mechanisms of irradiation-induced loops and precipitates. The implementation of electron tomography for Fe-Cr alloys may allow the first experimental observation of 3D morphology of irradiation-induced defects. The 3D reconstructions could provide a different insight on the defect configurations and therefore their possible behavior under irradiation. The collected data of this project will contribute to validate the possible mechanisms of the formation of mysterious loops in Fe-Cr alloys, and to improve the historic Nelson-Hudson-Mazey precipitate stability model for irradiation-induced precipitates.
Additional Info
| Field | Value |
|---|---|
| Abstract | This proposal aims to examine the 3D configuration of petal-shaped dislocation loops and heterogeneously distributed precipitates in ion-irradiated Fe-Cr model alloys. Ferritic-martensitic (FM) steels are promising candidates for the structural components in Generation IV fission reactors (such as liquid metal fast reactors and molten salt reactors) due to high temperature performance, good swelling and corrosion resistance. At specific material service temperatures, the formation of dislocation loops and irradiation-induced precipitations in irradiated FM steels can significantly influence the material properties. Our recent TEM studies have observed intriguing petal-shaped loops and precipitate denuded zones near carbides and dislocations in Fe-Cr model alloys. However, conventional 2D-projection TEM images are insufficient to understand the relationship between the 3D structures of these features. In this proposal, we pursue further electron tomography study to explore the 3D distribution and formation mechanisms of irradiation-induced loops and precipitates. The implementation of electron tomography for Fe-Cr alloys may allow the first experimental observation of 3D morphology of irradiation-induced defects. The 3D reconstructions could provide a different insight on the defect configurations and therefore their possible behavior under irradiation. The collected data of this project will contribute to validate the possible mechanisms of the formation of mysterious <001> loops in Fe-Cr alloys, and to improve the historic Nelson-Hudson-Mazey precipitate stability model for irradiation-induced precipitates. |
| Award Announced Date | 2023-02-08T10:52:20.937 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Kory Linton |
| Irradiation Facility | None |
| PI | Yajie Zhao |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 4597 |