NSUF 23-4723: Effect of ion irradiation and dose rates on 316LY oxide-dispersion-strengthened steel additively manufactured by laser-directed energy deposition
Oxide dispersion strengthened (ODS) alloys are promising candidates for advanced nuclear reactors due to the presence of a high number density (~1024 m-2) of small (5-50 nm) oxide particles such as (Y2O3) dispersed within a metallic matrix. Conventional manufacturing of ODS alloy includes numerous steps such as long hours of mechanical alloying followed by canning, degassing, and hot extrusion or hot isostatic pressing making scale-up manufacturing of these alloys extremely unviable. Our approach was to utilize additive manufacturing (AM) particularly laser directed energy deposition (LDED) of powder feedstock atomized with elemental yttrium to eliminate mechanical alloying and significantly reduce the numerous steps in manufacturing. The Microstructure of the samples was characterized by electron microscopy, and mechanical properties were measured using a tensile test and nanoindentation. Further, the thermal stability of the LDED-produced ODS steels was evaluated. As-printed samples showed a cellular structure with Si-Mn-Y-O-enriched nanoparticles that were found to be amorphous. After 100 hrs at 1000°C in an argon atmosphere, a partially recrystallized microstructure with a decrease in the number density of Y-O-enriched nanoparticles with crystalline structure was revealed. The as-printed (600 W, 600 mm/min) samples exhibited an ultimate tensile strength of 774 MPa and an elongation at a break of 22%. A lower ultimate tensile strength of 592 MPa and higher elongation of 42% was measured after 100 hrs at 1000°C. For this project, 3.0 MV NEC tandem accelerator at TAMU will be used for high dpa Fe self-ion irradiation. Irradiation will be performed in a high vacuum chamber along the beamline equipped with liquid nitrogen traps and multiple beam deflection setups for filtering contaminants. ODS samples will be irradiated by 5 MeV Fe self-ions for doses equivalent to 50 and 100 peak dpa at 575°C. The doses will be determined by using SRIM code under KP mode. Post-irradiation examination will include detailed microstructural studies using TEM and APT. The timeline for performing irradiation and post-irradiation examination will be between June and December 2023. The scientific outcome will be our understanding of the irradiation performance of novel ODS alloys additively manufactured via LDED.
Additional Info
| Field | Value |
|---|---|
| Abstract | Oxide dispersion strengthened (ODS) alloys are promising candidates for advanced nuclear reactors due to the presence of a high number density (~1024 m-2) of small (5-50 nm) oxide particles such as (Y2O3) dispersed within a metallic matrix. Conventional manufacturing of ODS alloy includes numerous steps such as long hours of mechanical alloying followed by canning, degassing, and hot extrusion or hot isostatic pressing making scale-up manufacturing of these alloys extremely unviable. Our approach was to utilize additive manufacturing (AM) particularly laser directed energy deposition (LDED) of powder feedstock atomized with elemental yttrium to eliminate mechanical alloying and significantly reduce the numerous steps in manufacturing. The Microstructure of the samples was characterized by electron microscopy, and mechanical properties were measured using a tensile test and nanoindentation. Further, the thermal stability of the LDED-produced ODS steels was evaluated. As-printed samples showed a cellular structure with Si-Mn-Y-O-enriched nanoparticles that were found to be amorphous. After 100 hrs at 1000°C in an argon atmosphere, a partially recrystallized microstructure with a decrease in the number density of Y-O-enriched nanoparticles with crystalline structure was revealed. The as-printed (600 W, 600 mm/min) samples exhibited an ultimate tensile strength of 774 MPa and an elongation at a break of 22%. A lower ultimate tensile strength of 592 MPa and higher elongation of 42% was measured after 100 hrs at 1000°C. For this project, 3.0 MV NEC tandem accelerator at TAMU will be used for high dpa Fe self-ion irradiation. Irradiation will be performed in a high vacuum chamber along the beamline equipped with liquid nitrogen traps and multiple beam deflection setups for filtering contaminants. ODS samples will be irradiated by 5 MeV Fe self-ions for doses equivalent to 50 and 100 peak dpa at 575°C. The doses will be determined by using SRIM code under KP mode. Post-irradiation examination will include detailed microstructural studies using TEM and APT. The timeline for performing irradiation and post-irradiation examination will be between June and December 2023. The scientific outcome will be our understanding of the irradiation performance of novel ODS alloys additively manufactured via LDED. |
| Award Announced Date | 2023-06-01T09:01:46.407 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Lin Shao, Yaqiao Wu |
| Irradiation Facility | Accelerator Laboratory |
| PI | Tianyi Chen |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | None |