NSUF 25-5420: Radiation induced changes in oxide particles in 14YWT alloys produced from gas atomization reaction synthesis powders
Ferritic oxide dispersion strengthened (ODS) alloys are one of the most promising candidates for structural applications due to their high temperature strength, thermal stability, creep resistance, and swelling resistance under irradiation provided by a high density of nano-oxides. However, ODS alloys are traditionally produced using ball milling followed by multiple hot deformation steps, making the process time-consuming and expensive. Therefore, recent efforts focus on developing ODS alloys from gas atomization reaction synthesis (GARS) powders without any ball milling. However, hot and cold processing methods to produce cladding tubes result in various oxides, such as large Y2O3 particles and fine Y-Ti-O complex oxides. Our preliminary ex-situ irradiation results indicate that the stability of oxide particles are closely related to the initial processing conditions. We propose a dissolution mechanism in Y2O3 particles under irradiation based on the pre-existing deformation structures. Therefore, in order to investigate the evolution of the Y2O3 particles in the deformed materials at the early stages of the irradiation, in-situ ion irradiations will be performed. 3-mm foils for transmission electron microscopy (TEM) will be prepared by electropolishing and initial TEM characterization will be performed at Pacific Northwest National Laboratory (PNNL). In-situ irradiations at the Intermediate Voltage Electron Microscopy (IVEM) will be performed using heavy ion irradiations (1 MeV Kr) at 300 °C, 450 °C and 600 °C up to ~10 dpa. Further detailed characterization will be performed at PNNL. Ultimately, both high dose ex-situ irradiations and low dose in-situ irradiations will provide a fundamental understanding on the dissolution mechanisms of the large Y2O3 particles and defect evolution under irradiation in correlation with the initial processing history. Application of this understanding will deliver insights on the optimization of the processing routes of ODS cladding materials for next generation advanced reactors.
Additional Info
| Field | Value |
|---|---|
| Awarded Institution | Pacific Northwest National Laboratory |
| DOI | 10.46936/NSUF/60015382 |
| Embargo End Date | 2027-09-03 |
| Facility Tech Lead | Wei-Ying Chen |
| Irradiation Facilities | Intermediate Voltage Electron Microscopy (IVEM)-Tandem Facility |
| NSUF Call | FY 2025 RTE 2nd Call |
| PI | Eda Aydogan |
| PIE Facilities | Intermediate Voltage Electron Microscopy (IVEM)-Tandem Facility |
| Project Member | Dr Eda Aydogan, Materials Scientist - Pacific Northwest National Laboratory (https://orcid.org/0000-0002-4923-7549) |
| Project Type | RTE |