Thermal properties of glass-ceramic glazes with zirconium oxide added to multicomponent system SiO2-Al2O3-CaO-MgO-Na2O.

The aim of this study was to analyse the thermal properties of glazes from the SiO2-Al2O3-CaO-MgO-Na2O system during the addition of zirconium oxide. The paper describes the effect of the addition of zirconium oxide on characteristic temperatures obtained with a high-temperature microscope and a mechanical dilatometer. Based on these data, the course of the logarithm curves of the viscosity of the glazes was determined on the basis of the Vogel–Tamman–Fulcher model. The analysis of thermal effects during the heating and cooling of glazes was also carried out on the basis of measurements made by means of differential scanning calorimetry and analysis of the phase composition at selected temperatures. The obtained results constitute a comprehensive characteristic of the thermal properties of glazes, in which the amount of zirconium oxide increases—from 0 to 24 mass%. [ABSTRACT FROM AUTHOR]