This work studies the use of the CaO-Al₂O₃-SiO₂-TiO₂-ZnO (CASTZ)-based glass-ceramics, as a coating and bonding agent was observed according to the change in Al₂O₃ substitution amount. Heat-treatment at 1000℃ is the standard procedure for bonding glass-ceramics with Al₂O₃ ceramics. The properties of the glass-ceramics and coatings are examined using X-ray diffraction, scanning electron microscopy, hardness measurements, and Raman analyses, to confirm the actual bonding morphologies and thermal expansion coefficients. Titanite (CaTiSiO₅) and willemite (Zn₂SiO₄) crystal phases are observed depending on the amount of Al₂O₃ substitution, and as the substitution amount increases, anorthite (CaAlSi₂O₈) crystal phases appear together. At this time, the microstructure densification and hardness change with variation in the heat-treatment temperature, indicating structural impact on glass, which is confirmed by Raman spectroscopy. A comparative analysis of the coefficients of thermal expansion between the substrate and glass-ceramic, along with actual bonding, reveals an increase in the bonding and wettability at higher Al₂O₃ substitution levels.

Keywords: Glass-ceramics, CTE, Titanite, Hardness, Microstructure