CoO-doped MgO-Al_2O_3-SiO_2-colored transparent glass-ceramics with high crystallinity

摘要

To obtain CoO-doped MgO-Al2O3-SiO2 (MAS)-colored transparent glass-ceramics with high crystallinity, the glass with the composition 21MgO-21Al(2)O(3)-54SiO(2)-4B(2)O(3)-0.2CoO (in mol %) was prepared by conventional melt quenching technique and subsequently thermal treated at several temperatures. The crystallization behavior of the glass, the precipitated crystalline phases and crystallinity were analyzed by X-ray diffraction (XRD). The microstructure of the glass-ceramics was characterized by field emission scanning electron microscopy (FSEM). The transmittance of glass-ceramic was measured by UV spectrophotometer. The results show that a large amount of alpha-cordierite (indianite) with nano-size was precipitated from the glass matrix after treatment at 1020 degrees C for 3 h. The crystallinity of the transparent glass-ceramic reached up to 97%. Meanwhile, the transmittance of the glass-ceramic was 74% at 400 nm with a complex absorption band from 450 nm to 700 nm. In addition, this colored transparent glass-ceramic possessed lower density (2.469 g/cm(3)), lower thermal expansion coefficient (1.822 x 10(-6) /degrees C), higher Vickers hardness (9.1 GPa) and higher bending strength (198 MPa) than parent glass.