Phase formation in the Al2O3-, quartz-, and cordierite-zinc borosilicate glass composites

Phase formation in the Al2O3-, quartz-, and cordierite-zinc borosilicate (ZBS) glass composites was investigated. Zinc in the ZBS glass reacted with ceramics with formation of zinc compounds such as zinc silicate and zinc aluminate. In the Al2O3-ZBS glass composite, ZnAl2O4 with a spinel structure was observed at relatively low temperature of 700 °C. β-Zn3B2O6 of the high-temperature polymorph and α-Zn2SiO4 of willemite structure were formed at 800 °C in the quartz-ZBS glass composite and β-Zn3B2O6 disappeared above 850 °C whereas α-Zn2SiO4 was observed up to 900 °C. In the cordierite-ZBS glass composite, the cordierite phase was decomposed by the reaction with the ZBS glass with formation of α-Zn2SiO4 and ZnAl2O4.