چكيده به لاتين
The effect of temperature and additives on nucleation and growth of zinc silicate were investigated by means of DTA, XRD and scanning electron microscopy (SEM). The chemical composition of the frit was determined by FERRO. The main compounds of the glaze was based on (2:1:1) of frit, silica and zinc oxide. Oxides of nickel and titanium played the role of nucleating agent. Coloring oxides commonly used included cobalt, manganese and iron oxides. Soaking time on different temperatures and time periods were compared and the influence of heat-treatment on growth and size of the crystals were studied. The most effective heat treatment was the one with maximum temperature of 1200 °C, holding at 900 °C for an hour and then experiencing a fast temperature enhancement up to 1000 °C and soaking for 5 hours. In this study the effects of addition of CoO, NiO, TiO2, MnO2 and Fe2O3 on the final shape and color of crystals were also examined. The maximum diameter of grown crystals was about 2 cm which achieved by the batch with ZnO/SiO2=1.52.
Keywords: Glaze, Macro crystalline, Crystallization, willemite, Zinc silicate.
