Preparation And Properties Of Crystalline Glaze For Low Temperature And Fast Firing

Crystalline glaze is one of the art glazes with high ornamental value and decoration effect. The ornamental and artistic quality of ceramics can be advanced with the crystalline glaze. At present, the traditional crystalline glaze is mainly applied to art porcelain and domestic porcelain due to its high firing temperature (about 1300℃) and long firing period (about hours). It can not satisfy the requirements of low temperature and fast firing for building ceramics, and is difficult to apply in the building ceramic field. If the crystalline glaze achieve the low temperature and fast firing, it can not only increase kinds of the decorative building ceramics, satisfy with the artistic needs of people, but also accord with the needs of energy saving.The objective of this dissertation is to shorten the firing period, reduce the firing temperature, and decrease the production cost for the crystalline glaze. Zinc silicate crystalline glaze of the low temperature and fast firing was prepared through detailed study of the formulation and process, combined with the ternary phase diagram and the orthogonal experiments. In order to reduce the firing temperature of zinc silicate crystalline glaze, a variety of fluxing agents such as glass powder etc. were added to the glaze, and made the firing temperature down to 1200℃. The firing period was shortened to 70min by process innovating such as preloading crystal seed and dry glazing etc., which avoided the difficulty of glazing from low viscosity of the glaze at the same time.It can be found that the host lattice formed in the glaze prepared in this dissertation was willemite by the result of XRD study. The microstructure of crystalline glaze was analyzed by polarizing microscope. We found that the morphology of willemite is fibrillar, and there is small angle furcation phenomenon in the glaze. The formation mechanism of crystalline glaze was discussed in this dissertation. And the effect of process conditions(such as the weight of glaze and the size of crystal seed and heating and cooling system) on crystallization were investigated as well.The effect and the mechanism of CoO and CuO were mainly studied in this dissertation. Some metal ions can enter the willemite to replace the zinc ion. So these metal oxides added in crystalline glaze can change the color of crystal.