Determination of the crystallization mechanism of glasses in the system BaO/SrO/ZnO/SiO2 with differential scanning calorimetry

Abstract

In order to identify suitable volume nucleation agents in glasses, heat treatments and subsequent traditional microscopic investigations are necessary. Those analyses are laborious and time-consuming. Therefore, often DSC methods are used to get information about the preferred crystallization mechanism or adequate nucleation and growth temperatures. In principle, these non-isothermal methods are much faster. In this study, different glasses from the system BaO–SrO–ZnO–SiO2 were prepared. The pairs show only slight compositional variations but a clearly different crystallization behavior. Each pair consists of one glass, which shows volume crystallization and another one, which crystallizes solely at the surface. The DSC results are correlated with the microstructures of the glass ceramics obtained from microscopic studies. It is shown that conventional DSC methods cannot give a distinct answer which crystallization mechanism really exists. One method was identified to securely determine the crystallization mechanism.

A threshold heating rate for single‐stage heat treatments in glass‐ceramics containing seed formers

“…In turn, the n values computed for LMAl‐Tu and LMAl‐Ts exhibited substantial discrepancies, with the untreated material plotting as high as 3.3(3) at 720°C. In these samples, the temperature dependence of the JMAK exponent was more evident and consistent with other glass‐ceramic systems 34,35 . In addition, the experimental data were used to calculate the overall JMAK activation energy for crystallization in the various samples (Figure 7B).…”

Impact of Zinc Oxide on the Structure and Surface Properties of Magnesium–Potassium Glass–Crystalline Glazes

“…It also reduces surface properties, such as chemical resistance and mechanical strength. The addition of zinc oxide to glazes affects the color of the glaze when pigments are used, and the final color of underglaze paints [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”

The Effect of SrO Addition on the Recrystallization of ZrSiO4 in Raw Glass–Ceramic Glazes from the SiO2-Al2O3-CaO-MgO-K2O-ZrO2 System

“…Fluxing raw materials play an important role; their presence and action can influence the crystallization processes of new phases, as the well as dissolution and recrystallization. Flux raw materials are one of the components of glazes, but their selection and quantity will have an actual impact on the phase composition of the fired glaze and the resulting properties [21][22][23][24][25][33][34][35][36][37].…”