Viscosity of Liquid Mercury and Hg-In Alloys (Studies on the Viscosity of Liquid Metals (II))

The viscosities of mercury and the Hg-In system have been determined by the capillary method. In pure mercury, the so-called “pre-freezing” phenomenon, which shows a considerably larger viscosity than that expected in ordinary exponential temperature dependence near the freezing point, has been observed. The phenomenon can be explained on the basis of formation of clusters in the liquid.The viscosity measurement was also carried out on the liquid Hg-In system, which contains eutectics and intermetallic compounds. For this systems, the isothermal viscosities did not vary with composition in a linear manner. The viscosity-composition curves have inflection points at the Hg-35 at%In eutectic composition, and also have sharp maxima in ∂η⁄∂C at the Hg-50 at%In (HgIn) composition, where the compound is formed in the solid state. The data suggest that clusters presumably exist in the liquid at the composition of intermetallic compound (HgIn) and its vicinities.