Author

Abstract

The effect of the alkali oxide content on viscosity has been studied
for sodium-potassium borate glasses. The deviation of viscosity values from
additivity has been modeled to investigate the effect of partial substitution
of one alkali oxide for another. Published data on isokom temperatures and
activation energies for sodium-potassium borate glass compositions has
been utilized along with L2-regression optimization technique for analysis.
It is found that both linear and nonlinear relations determine the
viscosity coefficients associated with chemical components of the glasses
under study. This model allows the calculation of viscosity for a given
temperature and accordingly, the fusion temperature of these glasses.
Furthermore, the established model relations show first and second order
mixed alkali effect on viscosity.

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