| Abstract Scope |
This paper firstly established a set of thermodynamic descriptions for the Mg-Gd system by means of CALPHAD approach, which show better agreement with the experimental phase equilibria and thermochemical data in the literature than the previous assessments. In terms of diffusion coefficients, the HitDIC software (https://hitdic.com/) was employed to evaluate the diffusion coefficients of solutions and compounds, from which the atomic mobilities were obtained by using the DICTRA software. Moreover, based on the obtained thermodynamic descriptions, the composition and temperature-dependent liquid-solid interfacial energies for Mg-Gd system was also evaluated using our developed OpenIEC code (https://github.com/openiec).
Subsequently, the established CALPHAD thermodynamic, atomic mobilities and interfacial energy descriptions were coupled with the phase-field model with finite interface dissipation, and three-dimensional phase-field simulations of evolution of the primary (Mg) dendrites during the solidification of Mg-Gd alloy were carried out. The simulation results are in good agreement with the experimental data. |