Accurate Predictions for the Viscosities of Pure Liquid Metals

摘要

The Andrade formula for the melting-point viscosity was re-examined in order to more accurately predict the viscosities of liquid metals for which experimental data are lacking. A closer re-examination showed that the Andrade coefficient C_A can be determined for the respective liquid metals on the basis of the relationship of a periodic variation in C_A values with atomic number. For this, a relationship between viscosity and surface tension for liquid metals was also derived, based on the new parameter. Using these two equations, the viscosities of various liquid refractory and rare-earth metals were predicted. The uncertainties in viscosity predictions using the new equations are expected to fall within the range of uncertainties associated with the experimental measurements made in the future. Recommended data are collected for the experimental viscosities of liquid metallic elements. However, it should be noted that the viscosity values for germanium, silicon, manganese and the refractory metals (Ti, Zr, Hf, V, Cr, Pd) are considerably, or highly, uncertain.