Effect of nucleating agents and heat treatments on the crystallization of magnesium aluminosilicate transparent glass-ceramics.

The crystallization behavior and transparent property of MgO-AlO-SiO (MAS) glasses with TiO and TiO+ZrO as nucleating agents were discussed by differential thermal analysis, X-ray diffraction, field emission-environment scanning electron microscope, energy dispersive spectrum and UV-VIS-NIR scanning spectrophotometer. It was found that the glass crystallized at 950 °C with ZrO less than 3% could obtain transparent glass ceramic, which presented purple to colorless. With the nucleating agent additives (5% TiO+3% ZrO), the colorless transparent glass-ceramics with spinel as the main crystal phase could be prepared, and the transmittance reached about 80%. As the crystallized temperature increase to 1 000 °C, besides spinel(MgAlO), sapphirine (MgAlSiO) and ZrTiO precipitated from matrix glass, and the transmitance of glass-ceramic decreased. [ABSTRACT FROM AUTHOR]