Viscosity of Ga-rich alloys in the Ga-In-Sn system

The viscosity of Ga-In-Sn liquid alloys has been measured from liquidus temperature to 1200 K in the Ga-rich corner (content of gallium above 71 at. %) using an oscillating cup viscometer. The temperature dependence of the viscosity of the investigated alloys is well described by the Arrhenius law. Isotherms of the viscosity for Ga-In-Sn liquid alloys in the Ga-rich corner can be represented as a linear dependence on the gallium content. The viscosity of the investigated alloys near the liquidus temperature has a positive deviation from the ideal value. These alloys behave as ideal solutions at higher temperatures. As the comparison of existing phenomenological models describing the viscosity as a function of composition to the experimental data is unsatisfactory, a new model for the viscosity has been developed in the present work using the concentration-concentration fluctuations structure factor in the long-wavelength limit. The agreement between the model calculation and experimental data for Ga-based alloys is excellent. •The viscosity of Ga-In-Sn melts was measured up to 1200 K in the Ga-rich corner.•The measurement was carrying out using the oscillating cup viscometer.•Viscosity isotherms of the melts have a linear dependence on the Ga content.•An improved model for calculating viscosity has been developed.•This model exactly describes the viscosity of Ga-based eutectic systems.