The crystallization behavior and thermal expansion properties of β-eucryptite prepared by sol–gel route

Lithium–aluminosilicate glass–ceramics in the form of eucryptite were synthesized through sol–gel technique by mixing boehmite sol, silica sol and lithium salt and sintering at different temperatures for further analysis. Thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), IR analysis and dilatometry were done to study sintering characteristics, phase transformation and thermal expansion behavior on the sintered specimens. XRD and FTIR results confirmed that crystallization of β-eucryptite took place at about 600 °C, substantial increase of β-eucryptite was observed in the specimens sintered at temperatures from 800 to 1300 °C. Trace amount of cristobalite also emerged at 600 °C and disappeared at 1300 °C. The thermal expansion behavior characteristics were found to be strongly influenced by crystalline phases in the specimens which depended on the sintering temperatures.