About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
First principles Study of Precipitation in Al-Cu, Al-Li and Al-Cu-Li Alloys |
Author(s) |
Sha Liu, Javier Llorca |
On-Site Speaker (Planned) |
Javier Llorca |
Abstract Scope |
An analysis of precipitation in Al-Cu-Li alloys is carried out using first principles calculations. The formation enthalpies of the different phases at 0K determined with density functional theory and ground state phases and potential structures of Guinier Preston zones at low temperature are determined from the convex hull of the formation enthalpy. Then, the cluster expansion Hamiltonians are fitted from the formation enthalpy data using machine learning and the finite temperature thermodynamic properties of the different ground state phases are determined from low temperature expansions and Monte Carlo simulations with semi-grand canonical ensemble. In addition, the vibrational entropic contribution to the free energy of the phases is included using the harmonic approximation. This information is used to determine critical information (solvus temperatures, Gibbs free energy, etc.) of different metastable phases in the Al-rich part of the Al-Cu, Al-Li and Al-Cu-Li phase diagrams to optimize the heat treatments of these alloys. |
Proceedings Inclusion? |
Planned: |