Thermodynamic properties of Al in ternary lead-free solder Al-Sn-Zn alloys

Thermodynamic properties of Al were calculated using the molecular interaction volume model (MIVM) by analyzing the activities of components in the constitutive binary Al-Sn, Al-Zn and Sn-Zn subsystems of the ternary lead-free solder Al-Sn-Zn systems. The activities of Al content in the ternary system at three cross-sections with constant molar ratios of Sn:Zn = 2:1, 1:1 and 1:2, respectively, were calculated and compared with available experimental data at 973 K. Based on the agreement between the calculated activity values and corresponding literature data for Al-Sn-Zn alloys and their subsystems, the activity of Al content in the ternary Al-Sn-Zn system was estimated at the same cross-sections and mole ratios in the temperature range of 1073 K to 1373 K, respectively. It has been observed through the computed activity values of Al that the thermodynamic properties of the ternary Al-Sn-Zn systems do not change appreciably with temperature across the molar sections.