Effects of Melt Forming Rate on Microstructure of Glass-Ceramics

Lithium aluminosilicate glass with different melt forming rates were prepared by the melting method. The effect of forming rate on the microstructure of heat-treated glass-ceramics was analyzed using XRD, DTA, IR and SEM techniques. The results show that the replacement of some Al3+ for Si4+ occurred in the interior of glass with low forming rate in the process of slow cooling(1 cm·s-1), which led to the primary nuclei precipitated. The glass interior converted into a white β-spodumene structure after heat treatment. Meanwhile, because of rapid cooling of the glass surface, the nucleation did not occur obviously. A transparent and colorless β-quartz solid solution was formed after heat treatment. High melt forming rate(6 cm·s-1) led to rapid cooling in the interior of glass,too. A single β-quartz solid solution was formed on surface and in interior after heat treament.