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

Abstract

AbstractIn 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.