Abstract
The preparation of β-spodumene powder from alumina sol, silica sol and lithium nitrate solution by the sol-gel process, its sintering condition and properties of sintered bodies have been investigated. The crystallization temperature of the β-spodumene powder was estimated to be about 720°C by TG-DTA, and also it was confirmed by XRD that the crystallization temperature of β-spodumene in the firing process corresponded to this temperature. A sintering characteristic of powders obtained from different preparation conditions showed remarkable differences to the progress of densification and the thermal stability. Moreover, the microstructure of sintered bodies was influenced by preparation conditions of powder and firing temperature. In particural, the sintered bodies formed above 1100°C by using the powder, which was prepared at 600°C for 4h, incorporated large pores (ca. 10μm) in the grains. The thermal expansion and contraction curves showed reversible behavior in the process of heating and cooling, and the average thermal expansion coefficient was 1.4×10-6°C-1 (RT-1000°C).
