Thermodynamic Description of the Al-Fe-Mg-Ni-Si and Al-Cu-Fe-Mg-Ni Quinary Systems and Its Application to Solidification Simulation

Abstract

Based on the critical review of the available experimental phase equilibrium data for the constituent quaternary systems in the Al-Fe-Mg-Ni-Si and Al-Cu-Fe-Mg-Ni quinary systems, a set of self-consistent thermodynamic parameters for these systems has been obtained using the CALPHAD approach. In combination with the constituent binary, ternary and quaternary systems, the thermodynamic database for the quinary Al-Fe-Mg-Ni-Si and Al-Cu-Fe-Mg-Ni systems was developed. Comprehensive comparisons between the calculated and measured phase diagrams and invariant reactions showed that the experimental data were satisfactorily accounted for by the present thermodynamic description. The established database was used to describe the solidification behaviors of Al alloys 6063 (Al-0.39Si-0.20Fe-0.43Mg, in wt.%) and 2618 (Al-2.24Cu-1.42Mg-0.9Fe-0.9Ni, in wt.%) under Gulliver-Scheil non-equilibrium condition. The reliability of the present thermodynamic database was also verified by the good agreement between the Gulliver-Scheil calculation and experiment.