Solid-state fabrication of nano-structured oxide dispersion strengthened alloys for advanced nuclear applications

Oxide dispersion strengthened (ODS) alloys are candidate materials for several high temperature applications due to their excellent creep-rupture properties. Their superior radiation damage tolerance also makes them suitable for reactor core applications in advanced fission and fusion rectors core components. However, they are very expensive due to difficulties in synthesizing and fabricating ODS alloys. Developing solution to this problem at this moment can be impactful because: (1) The prospects of sustained fusion energy is increasing but structural materials technology to build them have not evolved, (2) The development of 4th generation fission reactors to replace ageing nuclear power plants need affordable materials to withstand higher irradiation damage and temperature, and (3) Advanced fuel development program for current fission reactors needs affordable fabrication process to increase the safety, fuel burnup while reduce the radioactive wastes. Hence, development of affordable ODS alloy synthesis and fabrication processes help the nuclear power plants to become more economical and safer. The exceptional properties of nano-structured ODS alloys are attributed to their microstructural conditions of oxide nano-clusters featuring very high number density, matrix/particle interfaces capable of trapping helium, and uniform distribution. Use of conventional manufacturing techniques that involve melting will destroy these unique microstructural features. In Phase I, feasibility of consolidating a microstructurally sensitive ODS alloy powder and extruding them into thin walled tubes in single step was demonstrated using SolidStirTM extrusion technology without destroying the microstructure. In Phase II, we propose to develop and commercialize a scaled up version of the SolidStir extrusion system to fabricate thin-walled ODS tubes to be used in verity of nuclear and non-nuclear applications. In addition, we also explore feasibility of economically in-situ synthesis ODS alloys during the fabrication process. Successful development and demonstration of the proposed technology for fabricating nano-structured ODS ferritic alloys will be directly impactful on current and future advanced nuclear programs in combating the climate crisis and providing energy security. Most importantly, the proposed manufacturing route has the potential to become a path breaking manufacturing route for microstructurally sensitive materials such as mechanically alloyed powders and harder to fabricate high temperature materials that will make the power generation more efficient and safer.