NSUF 11-313: Grain boundary microchemistry of ion irradiated Ferritic/Martensitic steels as determined by advanced microscopy techniques
The objective of this project is to determine the radiation-induced segregation (RIS) behavior of a 9 wt.% Cr model steel at varying amounts of damage (dose) at grain boundaries with different structures. It is predicted that grain boundaries with specific types of structure will be stronger sinks for point defects created during irradiation over other boundaries, resulting in varied RIS response from one boundary to another. The project requires the use of advanced microscopy techniques including focused ion beam fabrication and scanning transmission electron microscopy (STEM). Focused ion beam fabrication is needed to create samples of extremely small volume to reduce the magnetic affects of the sample while using STEM. A STEM with a field emission gun is necessary to create spot sizes on the same or smaller length scale than the segregation width to provide accurate concentration information at the grain boundary. Due to the complicated nature of the system, a large data set is needed to draw any conclusion on the segregation behavior of the irradiated model steel. It is anticipated that the research will provide insight into the RIS phenomena in Ferritic/Martensitic (F/M) steels at different grain boundary structures. The project is an experimental component to a larger scope project which includes a modeling element which will help determine the exact physics of the system. The data produced from this project will be used to benchmark the model, which is currently in development. The model steel used in this investigation simulates the microstructure of commercially available F/M steels and will also help understand segregation occurring in alloys such as T91 and NF616. Long term impact includes the ability to determine which grain boundary structures are resistant to irradiation and therefore more radiation resistant steels can be fabricated by the use of established grain boundary engineering techniques. The project is predicted to take 7 months to the complete. The fabrications of focused ion beam samples are estimated to take 2 months and the STEM investigation up to 3 months. Data analysis and final report writing will take another 2 months.
Additional Info
| Field | Value |
|---|---|
| Abstract | The objective of this project is to determine the radiation-induced segregation (RIS) behavior of a 9 wt.% Cr model steel at varying amounts of damage (dose) at grain boundaries with different structures. It is predicted that grain boundaries with specific types of structure will be stronger sinks for point defects created during irradiation over other boundaries, resulting in varied RIS response from one boundary to another. The project requires the use of advanced microscopy techniques including focused ion beam fabrication and scanning transmission electron microscopy (STEM). Focused ion beam fabrication is needed to create samples of extremely small volume to reduce the magnetic affects of the sample while using STEM. A STEM with a field emission gun is necessary to create spot sizes on the same or smaller length scale than the segregation width to provide accurate concentration information at the grain boundary. Due to the complicated nature of the system, a large data set is needed to draw any conclusion on the segregation behavior of the irradiated model steel. It is anticipated that the research will provide insight into the RIS phenomena in Ferritic/Martensitic (F/M) steels at different grain boundary structures. The project is an experimental component to a larger scope project which includes a modeling element which will help determine the exact physics of the system. The data produced from this project will be used to benchmark the model, which is currently in development. The model steel used in this investigation simulates the microstructure of commercially available F/M steels and will also help understand segregation occurring in alloys such as T91 and NF616. Long term impact includes the ability to determine which grain boundary structures are resistant to irradiation and therefore more radiation resistant steels can be fabricated by the use of established grain boundary engineering techniques. The project is predicted to take 7 months to the complete. The fabrications of focused ion beam samples are estimated to take 2 months and the STEM investigation up to 3 months. Data analysis and final report writing will take another 2 months. |
| Award Announced Date | 2011-05-17T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Yaqiao Wu |
| Irradiation Facility | None |
| PI | Kumar Sridharan |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 313 |