About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
In-Situ Synchrotron Study of Non-Equilibrium Processing of Nanoscale Oxide-Dispersion Strengthened Steel Powder |
| Author(s) |
Zongyang Lyu, Kevin Jacob , Rameshwari Naorem , Siddhartha Pathak , Andrey Yakovenko, Nicolas Argibay , Jordan Tiarks , Timothy Horn, Matt deJong, Iver Anderson |
| On-Site Speaker (Planned) |
Zongyang Lyu |
| Abstract Scope |
In this work, Fe-14Cr-3W-0.4Y-0.4Zr-0.18Ti (wt.%) was developed as an alternative to oxide-dispersion strengthened (ODS) ferritic stainless steel, termed “14YWT.” These ODS alloys are conventionally processed from blended powders by extensive(40-80h) mechanical alloying. Enabled by rapid solidification, gas atomization reaction synthesis (GARS) was used to directly fabricate metastable alloy powders for similar ODS alloys. “Warm” GARS powder consolidation by vacuum pressing and cross-rolling with subsequent heat-treatment promotes formation of nanoscale Y-Zr-Ti-oxide dispersoids and ODS alloy shapes, e.g., plates, sheets, and tubes. In-situ synchrotron X-ray diffraction measurements were conducted on as-atomized GARS powders (dia.< 20 µm) using linear heating profiles (up to 1100˚C). The (Cr, Ti)2O3 crystalline phase formed on powder surfaces during heating (~650˚C), but decomposed by about 800°C, essentially removing a sintering barrier. Metastable (Y, Zr)2Fe17 intermetallic compound (IMC) phase formed in intercellular regions upon rapid solidification but decomposed during heating (800 - 900°C). This IMC provided essential Y and Zr and a template for the formation of stable Y-(Ti, Zr)-O nanoparticles. At T>900°C, the pre-existing Y2O3 phase decomposed and provided additional Y and O sources for Y-(Ti, Zr)-O dispersoids. TEM revealed nano-sized stable Y-(Ti, Zr)-O particles (20 ±7 nm) in the ODS alloys, where finer nanoparticles were observed but without clear stoichiometry or crystal structure. The peak aging temperature (850°C) of as-rolled samples was found from annealing treatments and Vickers microhardness measurements. Results indicate good potential for ODS alloys from these GARS powders for advanced nuclear fission and fusion reactors. Work funded by USDOE-NE through Ames Lab contract DE-AC02-07CH11358. |
| Proceedings Inclusion? |
Undecided |