NSUF 21-4257: The sink strength and radiation parameter effects on microchemical evolution in dual-ion irradiated additively manufactured and wrought HT9
The objective of this project to investigate the Cr-rich α′ and Ni-rich precipitates as well as chemical segregation evolution in dual ion irradiated additively manufactured HT-9 using direct-energy-deposition (DED) technique (as-built and another heat with post-built heat treatment, AM-HT9) alloys as well as wrought (one heat, W-HT9) using atom probe tomography (APT). HT-9, with potential application for fast reactors, is known to have the formation of Cr-rich α′ precipitates and Ni-rich clusters under irradiation, which potentially leads to irradiation hardening and embrittlement of the material. Additionally, radiation induced segregation (RIS) is known to occur at dislocation loops and cavities, which affects the evolution of these microstructural features. It is of the particular interest to study the effects of the heat-to-heat variability, starting microstructures and sink strengths of AM- and W- HT9 with different processing history on their microchemical behavior under irradiation. STEM-EDS has been used to study the precipitates and clustering, while the quantitative data of those and the RIS data is still lacking. APT would allow for the determination of (i) the size, number density and, most importantly, the chemical composition of the precipitates, and (ii) the extent of RIS at dislocation loops and cavities. This project requires advanced microanalysis techniques including Focused Ion Beam (FIB) for sample preparation and APT for 3D reconstruction data collection. This result, together with the already completed STEM-EDS analysis, will provide a detailed evaluation of how different processing and sink strength conditions in the starting alloys lead to different variances in the microchemical behaviors under irradiation. The information gained from the proposed work will have a broad impact on nuclear materials field in terms of alloy microstructure design of ferritic-martensitic steel tailored by synthesis and post heat treatment parameters. This project is expected to take no more than 9 months to complete if awarded. Fabrication of APT samples using FIB techniques is estimated to take no more than 2 months. Data collection of APT samples is expected to take less than two weeks. Data analysis and reporting will take approximately 2 months from the date of initial data collection.
Additional Info
| Field | Value |
|---|---|
| Abstract | The objective of this project to investigate the Cr-rich α′ and Ni-rich precipitates as well as chemical segregation evolution in dual ion irradiated additively manufactured HT-9 using direct-energy-deposition (DED) technique (as-built and another heat with post-built heat treatment, AM-HT9) alloys as well as wrought (one heat, W-HT9) using atom probe tomography (APT). HT-9, with potential application for fast reactors, is known to have the formation of Cr-rich α′ precipitates and Ni-rich clusters under irradiation, which potentially leads to irradiation hardening and embrittlement of the material. Additionally, radiation induced segregation (RIS) is known to occur at dislocation loops and cavities, which affects the evolution of these microstructural features. It is of the particular interest to study the effects of the heat-to-heat variability, starting microstructures and sink strengths of AM- and W- HT9 with different processing history on their microchemical behavior under irradiation. STEM-EDS has been used to study the precipitates and clustering, while the quantitative data of those and the RIS data is still lacking. APT would allow for the determination of (i) the size, number density and, most importantly, the chemical composition of the precipitates, and (ii) the extent of RIS at dislocation loops and cavities. This project requires advanced microanalysis techniques including Focused Ion Beam (FIB) for sample preparation and APT for 3D reconstruction data collection. This result, together with the already completed STEM-EDS analysis, will provide a detailed evaluation of how different processing and sink strength conditions in the starting alloys lead to different variances in the microchemical behaviors under irradiation. The information gained from the proposed work will have a broad impact on nuclear materials field in terms of alloy microstructure design of ferritic-martensitic steel tailored by synthesis and post heat treatment parameters. This project is expected to take no more than 9 months to complete if awarded. Fabrication of APT samples using FIB techniques is estimated to take no more than 2 months. Data collection of APT samples is expected to take less than two weeks. Data analysis and reporting will take approximately 2 months from the date of initial data collection. |
| Award Announced Date | 2021-06-07T16:22:03.323 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Yaqiao Wu |
| Irradiation Facility | None |
| PI | Pengyuan Xiu |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 4257 |