Thermal expansion property of P_2O_5 doped lithium aluminosilicate glass-ceramic synthesized by sol-gel process

摘要

Lithium aluminosilicate (LAS) glass-ceramics with 0 - I 0 wt% phosphoric anhydride were prepared by sol-gel method and sintering at high temperature. Tetraethyl orthosilicate (TOF.S). aluminum nitrate, lithium carbonate were used as precursors. Differential thermal analysis (DTA), X-ray powder diffraction (XRD) and thermal expansion coefficient (TEC) were used to characterize the dried LAS gels and glass-ceramic blocks. The results suggest β-spodumene solid-solution is the only crystals phase in the P_2O_5 doped LAS glass-ceramics when sintering temperature is 950°C. The thermal expansion coefficient of the P_2O_5 doped LAS glass-ceramics range from -O.1×10~(-6)°C~(-1) to 1.2×10~(-6)°C~(-1). Compared with the conventional melt quenching method, this process route provides a low temperature and timesaving method for preparing LAS glass-ceramics.