Synthesis of glass-ceramic glazes in the ZnO-Al2O3-SiO2-ZrO2 system

Glazes in the ZnO-Al2O3-SiO-ZrO2 system with crystallization ability of gahnite ((ZnOAl2O3)-Al-.) and beta-quartz solid solution (beta qss) were synthesized. The compositions were designed based on calcium and magnesium oxide replacement (from a CaO-MgO-Al2O3-SiO2 glass-ceramic glaze system) with zinc oxide and simultaneous increasing aluminum oxide. By this replacement, diopside eliminated and co-precipitation of gahnite and zirconium silicate observed. However, a little addition of Li2O changes the crystallization path by precipitation of beta q(ss) and willemite (2ZnO(.)SiO(2)) at low temperatures (800-900 degrees C) which dissolved into glaze by development of firing temperature. The experiments showed that while the micro-hardness of gahnite-based glass-ceramic glazes is almost equal with the diopside based one, it is more than the traditional floor tile glazes. (c) 2006 Elsevier Ltd. All rights reserved.