About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Nanostructured Materials in Extreme Environments
|
Presentation Title |
Global Compositional Patterning and Self-organization in Irradiated Alloys |
Author(s) |
Gabriel Frank Bouobda Moladje, Sourav Das, Amit Verma, Robert S Averback, Pascal M. Bellon |
On-Site Speaker (Planned) |
Pascal M. Bellon |
Abstract Scope |
Past modeling and experiments have established that irradiation can induce the self-organization of phase-separating alloy systems into nanoscale compositional patterns (CP) owing to the competition between finite-range ballistic mixing and thermodynamically driven decomposition. We extend these results to self-organization reactions that include both grain interiors and grain boundaries (GBs). We introduce a phase-field model to investigate this coupled self-organization in model phase-separating A-B nanocrystalline alloys. GBs, described as arrays of dislocations, act as defect sinks where solute segregation and precipitation can take place owing to coupling between point defect and solute fluxes. Ballistic mixing, however, promotes homogenization of the composition field and thus dissolution of precipitates. This competition can result in CP at GBs and in the grain interiors. Steady-state phase diagrams predicted by the model determine the irradiation parameters required for the stabilization of these nanostructures. These predictions are tested on Al-base and Ni-base alloys subjected to ion irradiation. |
Proceedings Inclusion? |
Planned: |
Keywords |
Phase Transformations, Modeling and Simulation, Nuclear Materials |