Calculation of the Viscosities of Multicomponent SiO2-Based Oxide Solutions Using the Viscosities of Two-Component SiO2-MxOy Systems in the SiO2 Concentration Range 65-75%

A relation is derived to calculate the viscosity of a multicomponent SiO2-based oxide solution as a function of the ionic fractions of the cations that make up the oxide solution. This relation can be used to predict the concentration-induced change in the viscosity and to calculate its value using the data on the viscosities of two-component SiO2-MxOy liquid solutions in the silicon dioxide concentration range 65-75 wt % at fixed temperatures. This relation is derived using the concept of an oxide solution as the superposition of the elementary structures of cations with respect to each other. Moreover, cations of the same kind are located around an oxygen anion. Cation sites are filled in such a way that four cations of the same kind are located around an oxygen anion. The accepted model assumes that all cations have the same size and the same charge and differ only in kind. The resulting calculation formula is a polynomial. To find the unknown coefficients in the viscosity equation as functions of composition, a probabilistic model is proposed to take into account the order of extraction of cations from a cationic mixture on the assumption that the change in the viscosity as a function of composition is similar to the probability of extraction of a certain set of cations from a cationic mixture. For an activation model of viscosity, regression relations are obtained for the dependences of the activation energy of viscous flow and the preexponential factor on the ionic fraction of the second component in SiO2-MxOy systems. The viscosities calculated by the derived relation are compared with the experimental data on the viscosities of multicomponent oxide silicate melts. The results of the comparative analysis show satisfactory agreement between the calculated and experimental viscosities.