Thermodynamic modeling of the Al–Mg–Na system

Sodium is an undesired impurity element in aluminum–magnesium alloys. In the present work, the binary Al–Na and Mg–Na systems were modeled by computational thermodynamics using the CALPHAD approach. Self-consistent thermodynamic parameters of the binary systems were obtained. Combined with the Al–Mg modeling in the literature, the phase equilibria of the ternary system were calculated using Thermo-Calc software. Isothermal and isopleth sections of the ternary system as well as the liquidus projection were presented. The present work contributes to the thermodynamic database developments and the study of the impurity effects on processing of aluminum and magnesium alloy systems.