No ball milling nee de d: Alternative ODS steel manufacturing with gas atomization reaction synthesis (GARS) and friction-based processing

Oxide dispersion strengthened (ODS) steels are promising structural materials for future fusion reactors. The high-density (similar to 10(23) /m(3) ) of highly stable Y-(Ti)-O nano-oxides provide high sink strength for radiation resistance and high-temperature ( > 650 degrees C) creep strength. Concomitantly, helium management is enabled by trapping high density (similar to 10 23 /m 3 ) of small ( < 3 nm) helium bubbles in the vicinity of nano-oxides. However, conventional route of making ODS steels involves prolonged ball milling, canning, degassing, and laborious thermo-mechanical processing (TMP). Such route, especially the batch-by-batch ball milling step, faces persistent challenge with scalability and high costs. Gas atomization reaction synthesis (GARS) method has demonstrated the potential of making precursor ODS steel powders without ball milling, but the nano-oxide density was around 10 (21) /m(3) in the final consolidated form by conventional TMP. Taking advantage of GARS precursor powder, we use friction-based processing, including friction consolidation and extrusion, to manufacture ODS steel with further improved nano-oxide characteristics. Preliminary results showed that Y/Ti/O species were intimately mixed and rapidly reacted to form nano-oxides with a number density of similar to 10(2) /m(3) .

Automated summary

Oxide dispersion strengthened (ODS) steels are promising structural materials for future fusion reactors. They have high-density nano-oxides that provide radiation resistance and high-temperature creep strength. Helium management is also enabled by trapping small helium bubbles near the nano-oxides. However, the conventional manufacturing route faces challenges with scalability and cost. The gas atomization reaction synthesis (GARS) method, combined with friction-based processing, shows potential in improving the nano-oxide characteristics.