PHYSICAL PROPERTIES AND CHEMICAL DURABILITY OF SELECTED ZIRCONIA CONTAINING SILICATE GLASSES

Density, thermal expansion, glass transition temperature, refractive index, molar refractivity and chemical durability of five- and six-component glasses with as weighted composition xNa(2)O center dot(15-x)K2O center dot yCaO center dot(10-y)ZnO center dot zZrO(2)center dot(75-z)SiO2 (x = 0, 7.5, 15; y = 0, 5, 10; z = 5, 7) were measured. The obtained experimental data were merged together with the previous results obtained for analogous glasses with lower zirconia content. The full set of glasses enabled the quantitative statistical estimation of possible mixed-oxide effects. The results of the multilinear regression analysis pointed out the ideal behavior of molar volume and molar refractivity. The strongest influence of mutual oxide interactions was found for chemical durability and glass transition temperature. The regression analysis of compositional dependence of metastable melt thermal expansion coefficient practically failed. The need of property-composition study based on the thermodynamic model was pointed out. Qualitatively the obtained results confirmed those previously obtained for the analogous glasses with zirconia content reaching up to 3 mol. %.