About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
Stability of Immiscible Nanocrystalline Alloys in Compositional and Thermal Fields |
Author(s) |
Joseph Monti, Emily Hopkins, Fadi Abdeljawad, Khalid Hattar, Brad Boyce, Remi Dingreville |
On-Site Speaker (Planned) |
Joseph Monti |
Abstract Scope |
Alloying is often employed to stabilize nanocrystalline materials against microstructural coarsening via kinetic or thermodynamic stabilization mechanisms. The interplay between these mechanisms depends on grain-boundary character and on any imposed compositional and thermal fields that further promote or inhibit grain growth. We study the stability of immiscible nanocrystalline alloys in homogeneous and heterogeneous compositional and thermal fields by using a multi-phase-field formulation for anisotropic grain growth with grain-boundary character-dependent segregation properties. Our results demonstrate the role of grain-boundary heterogeneity on solute-induced stabilization. We show that increasing the solute concentration progressively slows grain growth via both stabilization mechanisms, while increasing the temperature generally weakens thermodynamic stabilization effects due to entropic contributions. Finally, we demonstrate as a proof-of-concept that spatially-varying compositional and thermal fields can be used to construct dynamically-stable, graded, nanostructured materials. We compare our model predictions to experimental results of microstructures in Pt-Au nanocrystalline alloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Computational Materials Science & Engineering, |