Estimation of the viscosities of melt for Sn-based ternary lead-free solder alloys

The proposed thermodynamic parameters were extended to the liquid ternary alloy system, and a prediction model of the viscosity for liquid alloy was proposed. The viscosity of the ternary liquid lead-free solder alloy was calculated using the thermodynamic parameters and the prediction model for viscosity of ternary liquid alloy. The results show that the calculated viscosity of the ternary liquid lead-free solder alloy is consistent with the reported experimental values, and the prediction model has good rationality. At the same time, compared with the complex Seetharaman model, Moelwyn-Hughes model and Kaptay model, the prediction model for viscosity of ternary liquid alloy depends only on the element's basic physical parameter (density, melting temperature, absolute atomic mass, electro-negativity, electron density, molar volume, and Pauling radius). The entire calculation process is relatively simple. Additionally, the proposed prediction model of viscosity can be applied to system calculations having similar physical and thermodynamic properties as ternary liquid Tin-based lead-free alloys.