Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10644375 | Calphad | 2005 | 9 Pages |
Abstract
Despite numerous investigations, all previous efforts on thermodynamic modeling of Al-Mg have suffered from inaccurate energetics of solid phases. In the present work, the first-principles calculations were performed using VASP based on the pseudo-potentials and a plane wave basis set. The enthalpies of formation of the ε-Al30Mg23 phase, end-members of the γ-Al12Mg17 phase, and three laves phases at the Al2Mg composition were calculated at 0 K. Special quasi-random structures (SQS's) were used to mimic random fcc and hcp solution phases, and their enthalpies of mixing were predicted by first-principles calculations. The Al occupancy in the γ-Al12Mg17 phase is also studied by first-principles calculations, and the sublattice model (Mg)5(Al,Mg)12(Al,Mg)12 was verified as the proper model to describe the γ-Al12Mg17 phase. The complete thermodynamic description of the Al-Mg binary system was evaluated by this combined CALPHAD/first-principles calculations approach and was shown to be in a good agreement with experimental data with better defined energetics of solid phases than the previous modeling.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Yu Zhong, Mei Yang, Zi-Kui Liu,