About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Modeling, AI Applications, and Method Development in Nuclear Materials
|
| Presentation Title |
A Cluster Expansion Free Energy Input for CALPHAD Description of δ-PuGa and δ-PuU |
| Author(s) |
Derick Ober, Aaron Kohnert, Sarah Hernandez |
| On-Site Speaker (Planned) |
Derick Ober |
| Abstract Scope |
The thermodynamic properties of plutonium and its alloys are notoriously complex, and
the general costs of plutonium experimentation hinder data collection. While existing data
can be extrapolated using the CALculation of PHAse Diagrams (CALPHAD) framework,
CALPHAD cannot generate new data. Meanwhile, first-principles methods such as Density
Functional Theory (DFT) can provide the necessary energetics, but only at zero Kelvin. In
this investigation, we use the alloy cluster expansion trained on first-principles calculations
to predict finite temperature free energies using Monte Carlo calculations. These free
energies can be approximated using the parametric CALPHAD free energy formalism,
where learned parameters are stored in standard thermodynamic database format. We
validate this method on the well-characterized FCC δ-phase solid solution Pu–Ga and Pu–U systems, showing reliable reconstruction of experimentally derived free energy
parametrizations. This successful validation encourages application of the workflow to
thermodynamic regimes and phases with little to no experimental data. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Nuclear Materials, |