Mechanical Properties of Nano-Crystalline Glaze for Wall Tiles Prepared by Controlling TiO2 Nucleating Agents

In this paper, TiO 2 is substituted as a nucleating agent in opaque glaze to produce nano-crystalline glaze with high hardness. The crystallization mechanism of glaze was calculated by non-isothermal thermal analysis by Differential Thermal Analysis (DTA), and the glaze was heat treated at the crystallization temperature ( T p ). In the case of glaze (88G20T), in which TiO 2 was substituted by 20 wt% showed surface crystallization behaviors because the Avrami constant ( n ) was 1.18 and the activation energy ( E ) values were 747.0 kJ/mol at the crystallization temperature ( T p 2 ). The microstructure of the glazes without heat-treatment showed that phase separation transferred from spinodal to nucleation-growth as TiO 2 substitution increased. The size of droplets was nano-sized, below 100 nm. The glazes heated at the crystallization temperature ( T p ) and crystal size of several hundred nm to several μ m was observed. The surface hardness of the crystalline glaze showed a high hardness of 6.74 GPa and the degree of crystallization was 47.5% at 80G20T after heat treatment at T p 2 (1207 °C).