NSUF 11-305: Atomic scale analysis of ODS steels before and after high dose ion implantation
Oxide dispersion strengthened (ODS) steels are considered viable candidate structural materials in Gen IV fission reactors. The proper design of these alloys requires a detailed understanding of the processing /microstructure relationships while safe long term use requires understanding the microstructural stability under irradiation. Brocq et al. (2010) investigated the role of ball milling parameters on the resulting oxide dispersion. Ball milling initially leads to the dissolution of the oxide phase but eventually promotes the nucleation of oxide clusters. It is unclear whether the formation of oxide particle is specific to the chosen ball milling parameters and how this initial nucleation affects the resulting consolidated microstructure. In a first instance, the proposed work will focus on characterizing an ODS Fe-18Cr in powder form (after ball milling and before consolidation) and in consolidated form using atom-probe tomography to confirm the presence of oxide clusters before consolidation and correlate this initial oxide distribution to the final observed distribution present in the consolidated material. Specimens will be prepared using a focused ion beam lift-out approach. Conflicting results have been published on the radiation behavior of ODS steels suggesting that the oxide particles may or may not dissolve – the dissolution however appears to be function of dose. We propose to characterize 2 ODS Fe-18Cr alloys before and after ion implantations to very high doses (100dpa at 300oC and 200dpa at 500oC). The alloys contain either MgO or Y2O3 nanoscale oxide particles and have been irradiated at the Jannus facility. Characterization will be performed by atom-probe tomography and specimens will be prepared using a focused ion beam tool for lift-out procedure. Overall, the proposed work is expected to take 3 months.
Additional Info
| Field | Value |
|---|---|
| Abstract | Oxide dispersion strengthened (ODS) steels are considered viable candidate structural materials in Gen IV fission reactors. The proper design of these alloys requires a detailed understanding of the processing /microstructure relationships while safe long term use requires understanding the microstructural stability under irradiation. Brocq et al. (2010) investigated the role of ball milling parameters on the resulting oxide dispersion. Ball milling initially leads to the dissolution of the oxide phase but eventually promotes the nucleation of oxide clusters. It is unclear whether the formation of oxide particle is specific to the chosen ball milling parameters and how this initial nucleation affects the resulting consolidated microstructure. In a first instance, the proposed work will focus on characterizing an ODS Fe-18Cr in powder form (after ball milling and before consolidation) and in consolidated form using atom-probe tomography to confirm the presence of oxide clusters before consolidation and correlate this initial oxide distribution to the final observed distribution present in the consolidated material. Specimens will be prepared using a focused ion beam lift-out approach. Conflicting results have been published on the radiation behavior of ODS steels suggesting that the oxide particles may or may not dissolve – the dissolution however appears to be function of dose. We propose to characterize 2 ODS Fe-18Cr alloys before and after ion implantations to very high doses (100dpa at 300oC and 200dpa at 500oC). The alloys contain either MgO or Y2O3 nanoscale oxide particles and have been irradiated at the Jannus facility. Characterization will be performed by atom-probe tomography and specimens will be prepared using a focused ion beam tool for lift-out procedure. Overall, the proposed work is expected to take 3 months. |
| Award Announced Date | 2011-02-03T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Yaqiao Wu |
| Irradiation Facility | None |
| PI | Emmanuelle Marquis |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 305 |