Chemical durability of zircon containing glass-ceramic glazes

Abstract

Abstract The corrosion behavior of zircon containing glass-ceramic glazes was studied by examining four different glaze compositions. Glazes with different SiO 2 and ZrO 2 contents were prepared. Chemical resistance of glazed surfaces was tested by immersion of glazes in strong acid solution (HCl-18 vol%). XRD studies of the surfaces before and after immersion did not detect any changes in types and amount of crystalline phases. Zircon was formed as the major phase besides, quartz and anorthite were detected as secondary phases for all samples before and after immersion. Surface examination and SEM-EDX analysis showed that the corrosion mechanism of glazes was directly affected by the composition of the glassy phase. When ZrO 2 dissolved in the glassy phase, the formation of soluble Zr-containing components accelerated the corrosion by the dissolution of the glassy phase and EDX study revealed the compositional change of the glassy phase. When glassy phase did not contain ZrO 2 , corrosion occurred via dissolution of grain boundary phase around the zircon grains instead of dissolution of the glassy phase.