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

Abstract Glazes in the ZnO–Al 2 O 3 –SiO 2 –ZrO 2 system with crystallization ability of gahnite (ZnO·Al 2 O 3 ) and β-quartz solid solution (βqss) were synthesized. The compositions were designed based on calcium and magnesium oxide replacement (from a CaO–MgO–Al 2 O 3 –SiO 2 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 Li 2 O changes the crystallization path by precipitation of βq ss and willemite (2ZnO·SiO 2 ) at low temperatures (800–900 °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.