About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
Understanding Guinier-Preston (GP) Zones in Mg Alloys from First-Principles Thermodynamics |
Author(s) |
Yuan-Chen Gao, Du Cheng, Kang Wang, Bi-Cheng Zhou |
On-Site Speaker (Planned) |
Bi-Cheng Zhou |
Abstract Scope |
Guinier-Preston (GP) zones are nanometer-sized solute clusters which form at the early stage of precipitation and are critical for the mechanical properties of alloys. The interplay between free energies of solute mixing, phase formation and interfaces, and the coherency strains which are responsible for the formation and morphology of GP zones are still controversial. I will discuss the use of a novel first-principles thermodynamic approach, mixed-space cluster expansion, to study GP zones in Mg alloys which accounts for both short-range chemical and long-range strain energy contributions. The atomic structures of GP zones and their metastable phase diagrams are predicted. It is found that the long-range strain energy caused by the size mismatch between constituents, especially its anisotropy, plays an important role in the formation of GP zones. Implications on using alloying to alter the coherency strain energy and tune the morphology and orientation of GP zones are discussed. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Phase Transformations, Magnesium |