About this Abstract |
Meeting |
Materials in Nuclear Energy Systems (MiNES) 2021
|
Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2021
|
Presentation Title |
Contextualizing Dispersoid Evolution within Friction Stir Welded and Ion Irradiated MA956 |
Author(s) |
Elizabeth M. Getto, Nicholas Nathan, Jack McMahan, Brad Baker, Stephen Taller |
On-Site Speaker (Planned) |
Elizabeth M. Getto |
Abstract Scope |
Understanding the co-evolution of dispersoids with the dislocation loops and network is critical for a comprehensive understanding of the response of friction stir welded (FSW) and oxide-dispersion-strengthened (ODS) steels to radiation. Ion irradiations were performed on FSW and ODS Fe-Cr-Al steel MA956 with 5 MeV Fe++ ions from 400 to 500°C at doses ranging from 50 to 200 dpa. Characterization was performed primarily with scanning transmission electron microscopy and energy-dispersive x-ray spectroscopy to investigate the Y-Al-O dispersoids, voids and dislocations. The co-evolution of the microstructure was explained as a function of the evolving defect kinetics, utilizing rate theory to calculate point defect concentrations, determine defect partitioning among sinks, and the increasing diffusivity of vacancies. Regardless of temperature, the dispersoids increased in diameter and decreased in number density, which was attributed to an Ostwald coarsening mechanism supported by calculations of the radiation enhanced diffusion and ballistic dissolution. |
Proceedings Inclusion? |
Undecided |