Thermodynamic assessment of Mg-Ga binary system
(1. School of Materials Science and Engineering, Central South University of Forestry and Technology,
Changsha 410004, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
3. Swiss Federal Laboratories for Materials Testing and Research,
Laboratory for Joining and Interface Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland;
4. School of Science, Hunan University of Technology, Zhuzhou 412008, China)
Changsha 410004, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
3. Swiss Federal Laboratories for Materials Testing and Research,
Laboratory for Joining and Interface Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland;
4. School of Science, Hunan University of Technology, Zhuzhou 412008, China)
Abstract: In order to obtain the thermodynamic description of the Mg-Ga binary system, the thermodynamic assessment of the system was carried out using the CALPHAD method through Thermo-calc® software package based on the evaluation of all available experimental data from the published literature. The solution phases, including liquid, hcp(Mg) and orthorhombic(Ga), were described by the substitutional solution model, of which the excess Gibbs energies were expressed with the Redlich-Kister polynomial. Meanwhile, all intermetallic compounds, Mg5Ga2, Mg2Ga, MgGa, MgGa2 and Mg2Ga5, were modeled as stoichiometric compounds. A set of self-consistent thermodynamic parameters formulating the Gibbs energies of various phases in the Mg-Ga binary system were obtained finally. The much better agreement is achieved between the calculated results and the reported experimental data.
Key words: Mg-based alloys; phase diagram; thermodynamic; CALPHAD method; Mg-Ga binary system