Surface Tension of GaInSnBiZn Liquid High-entropy Alloy

Abstract

As an emerging alloy material, high-entropy alloy has potential applications that distinguish it from traditional alloys due to its special physicochemical properties. In this work, a low melting point GaInSnBiZn high-entropy alloy was designed based on Miedema model, and its surface tension was measured by the continuous pendant-drop method. The results show that the intrinsic surface tension of GaInSnBiZn high-entropy alloy at 80 °C is 545±5 mN/m, and the surface tension of the liquid alloy is significantly reduced by the formation of surface oxide film. The surface tension of GaInSnBiZn high-entropy alloy was analyzed by using theoretical models (Guggenheim model, GSM (general solution) model and Butler model), and the thermodynamic characteristics of the surface tension formation were further verified by combining with thermodynamic calculations, among which the calculated results of Butler model were in good agreement with the experimental data. Meanwhile, it is found that the surface concentration of Bi in the alloy is much larger than the nominal concentration of its bulk phase, which contributes the most to the surface tension of the alloy, however, it contributes the least to the entropy of the alloy formation in combination with the Butler model.