Composition dependences of thermodynamical properties associated with Pb-free ternary,quaternary, and quinary solder systems

In the present study, Chou’s General Solution Model (GSM) has been used to predict the enthalpy and partial enthalpies of mixing of the liquid Ag–In–Sn ternary, Ag–In–Sn–Zn quaternary, and Ag–Au–In–Sn–Zn quinary systems. These are of technical importance to optimize lead-free solder alloys, in selected cross-sections: x_In/x_Sn = 0.5/0.5 (ternary), Au–In_0.1–Sn_0.8–Zn_0.1, Ag–In_0.1–Sn_0.8–Zn_0.1 (quaternary), and t = x_Au/x_In = 1, x_In = x_Sn = x_Zn (quinary) at 1173, 773, and 773 K, respectively. Moreover, the activity of In content in the ternary alloy system Ag–In–Sn has been calculated and its result is compared with that determined from the experiment, while the activities of Ag contents associated with the alloys mentioned above have been calculated. The other traditional models such as of Colinet, Kohler, Muggianu, Toop, and Hillert are also included in calculations. Comparing those calculated from the proposed GSM with those determined from experimental measurements, it is seen that this model becomes considerably realistic in computerization for estimating thermodynamic properties in multicomponent systems.