Crystallization of sodium calcium silicate glass for highly transparent glass-ceramics

Sodium-calcium-silicate glasses are the most widely used glasses in architectures, photovoltaics, etc. Development of highly transparent sodium-calcium-silicate glass-ceramics is important to extend the application areas. This work investigates the effect of glass composition on the crystallization and transmittance of sodium-calcium-silicate glasses containing ZrO2. It is found that concentration of Na2O in the glasses has large effect on the crystallization behaviors and transmittance of the glass-ceramics obtained. Higher concentration of Na2O in glasses leads to lower glass transition temperature and crystallization activation energy, facilitating the bulk crystallization. Lower concentration of Na2O in glasses results in the surface crystallization of glasses. Similarity in composition of crystalline grains and glass improves the transmittance of glass-ceramics up to above 75 % in the visible region, even when the grain size is as large as ∼150 µm. Results reported in this work are full of significance for the development of transparent sodium-calcium-silicate glass-ceramics.