The Crystallization and Fracture Toughness of Transparent Glass-ceramics with Various Al₂O₃ Additions for Mobile Devices

Abstract

Li₂O−Al₂O₃−SiO₂ (LAS) glass-ceramics were prepared by a melting method. Effects of different Al₂O₃ content on the structure, crystallization, transmittance and fracture toughness of LAS glass-ceramics were investigated by means of XRD, FESEM and other methods as well. The results showed that the glass transition temperature and crystallization temperature of samples increased as the content of Al₂O₃ increased from 4.1 wt% to 13.1 wt%, which restrained the precipitation of lithium disilicate crystals. The main crystalline phase of glass-ceramics transformed from lithium disilicate and petalite to silicon dioxide, which reduced the fracture toughness of glass-ceramics. When the Al₂O₃ content was 7.1 wt%, the specimen had outstanding transmittance and fracture toughness. The transmittance was 90.32%. The fracture toughness was 1.13 MPa · m^1/2. Compared with high-alumina glass, the fracture toughness of the glass-ceramic was greatly improved, and it could be used as a new type of protective material for mobile devices.

Keywords

transparent glass-ceramics / crystallization / Al₂O₃ / lithium disilicate / petalite