Viscosity of many-component glasses

The effect of composition on the viscosity (η) of multicomponent glasses is expressed as B = ∑ i = 1 N B i x i where B = T ln ( η / η ∞ ) is the activation energy (in K), Bi is the i-th component coefficient, xi is the i-th component mass fraction, T is the absolute temperature, and η∞ ≈ 10−5 Pa ⋅ s. The Bi coefficients for three composition regions (labeled as CVS-1&2, CVS-3, and CVS-4) containing various subsets of Al2O3, B2O3, Bi2O3, CaO, Cr2O3, F, Fe2O3, K2O, Li2O, MgO, MnO, Na2O, NiO, P2O5, SiO2, UO2, and ZrO2 as major components are summarized and compared. This paper presents a detailed account of the recent experimental study that generated viscosity data for the CVS-4 region of glass composition. Whereas CVS-1&2 is a well publicized dataset, CVS-3 viscosity data, though produced in 1995, are published and evaluated here for the first time. Limits of applicability of the composition models are discussed.