Viscosity and Electrical Conductivity of the Liquid Sn-3.8Ag-0.7Cu Alloy with Minor Co Admixtures.

The viscosity and electrical conductivity as structure-sensitive transport properties of the liquid metals and alloys are important for modeling of the melting and solidification processes. The viscosity and electrical conductivity data provide additional information about the influence of impurities on the structure and physicochemical properties of the liquid metal matrix, which is useful for understanding of structural transformations in the liquid state. In the present work, an impact of minor Co admixtures on the viscosity and electrical conductivity of liquid Sn-3.8Ag-0.7Cu alloy was studied. An increase in viscosity with minor Co admixtures is in a satisfactory agreement with model predicted data obtained from thermodynamic approaches and suggests a significant impact of interatomic interactions. Cobalt admixtures significantly affect the electrical conductivity, which gradually decreases with increasing the amount of Co. Additionally, the sample microstructure has been examined using x-ray diffraction and scanning electron microscopy analyses. The formation of Sn-based Co-Sn intermetallic compounds was detected in the alloys with more than 1 wt.% Co.