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Single (TiO2) and complex (TiO2 and ZrO2) nucleating agents were added in CaO–Al2O3–SiO2–ZnO–Na2O–K2O‐based multicomponent glass to investigate its crystallization behavior and physical properties according to the types and amounts of nucleating agents. Nonisothermal analysis revealed crystallization behavior with an activation energy (E) of 165.176–518.985 kJ/mol and Avrami constant (n) of.73–2.12 with the complex nucleating agent. X‐ray diffraction was used to observe the titanite and zircon crystalline phases in glass when using complex nucleating agents, and the crystallinity was found to be 43%–55%. Scanning electron microscopy and energy‐dispersive x‐ray spectroscopy were used to observe the plate‐shaped titanite and column‐shaped zircon crystalline phase in the glass matrix, and the glossiness was found to be decreased owing to the crystallization of the glass. The glass‐ceramic showed a higher hardness and fracture toughness value of 6.45–6.7 GPa and 1.54–3.35 MPa∙m1/2 when using the complex nucleating agent rather than when using the single nucleating agent. [ABSTRACT FROM AUTHOR]

MgO was added to the SiO2-Al2O3-CaO-ZrO2-based glaze to produce a high-hardness glaze by forming a composite crystal phase. The effects of MgO addition on the surface properties of the glaze were analyzed through crystal phase and microstructural investigations, and the whiteness, roughness, gloss, wear rate, and hardness were measured. When the amount of added MgO increased by 2.20 wt% or more, the diopside (MgCaSi2O6) crystal phase was observed via X-ray diffraction (XRD) and scanning electron microscopy (SEM), in addition to the zircon (ZrSiO4) crystal phase. All samples exhibited high whiteness and the surface roughness increased with increasing MgO content. At the same time, the gloss decreased significantly, resulting in a matte. The Vickers hardness test results of the glazed surface indicated high hardness values of 6.23–7.07 GPa with increased amounts of MgO. [ABSTRACT FROM AUTHOR]

In this study, TiO 2 was substituted as a nucleating agent to apply CaO–Al 2 O 3 –SiO 2 –ZnO (CASZ)-based glass to a high-hardness crystallized glaze, and the crystallization behavior and hardness of the glaze were observed with respect to the amount of TiO 2 substitution. X-ray diffraction and scanning electron microscopy analyses revealed that as the TiO 2 substitution increased, a titanite crystal phase was formed in the existing anorthite crystal phase, and the crystallinity of the glaze rapidly increased. In particular, the highest crystallinity of 83.8% was observed for 12.5 wt% TiO 2 substitution. The activation energy and Avrami exponent (n) of the glaze were calculated via non-isothermal analysis using differential thermal analysis, and surface crystallization behavior of n ≤ 2.5 was observed for all mixing ratios. The density of the glaze increased from 2.33 to 2.80 g cm−3 as the TiO 2 substitution increased. The hardness of the glaze showed the lowest value (3.12 GPa) for the sample without TiO 2 substitution and increased rapidly to 6.33 GPa or higher in the TiO 2 substitution specimens. [ABSTRACT FROM AUTHOR]