Preparation and Characterization of High-Strength Glass-Ceramics via Ion-Exchange Method

Lithium aluminosilicate glass-ceramics (LAS GCs) are ideal shell materials for mobile phones; however, the mechanical properties of LAS GCs are comparatively lower than that of other shell materials. In this work, the impact of TiO₂/(TiO₂ + ZrO₂) ratio on properties of LAS GCs was studied and the ion-exchange methods were applied to improve the mechanical properties of LAS GCs. The results show that LAS GCs with TiO₂/(TiO₂ + ZrO₂) = 1/2 exhibit the best flexural strength (109 MPa) and Vickers hardness (525 Kg/mm²). The as-prepared glass was nucleated at 560 °C for 1 h and crystallized at 720 °C for 0.5 h. The main crystalline phases of LAS GCs are β-quartz solid solution, β-spodumene solid solution, and Li₂SiO₃. Moreover, the flexural strength and Vickers hardness of LAS GCs with TiO₂/(TiO₂ + ZrO₂) = 1/2 further increased to 356 MPa and 838 Kg/mm² after an ion-exchange at 420 °C for 6 h in pure KNO₃ molten salt. The LAS GCs with enhanced mechanical strength have the potential to be applied as mobile phone back panels.