Effect of ZrO2 on crystallization behavior of lithium aluminosilicate glass-ceramic powders by polyacrylamide gel method
(1.黑龙江省哈尔滨市哈尔滨工业大学材料科学与工程学院2.Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001, China3.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)
Abstract: A novel method based on polyacrylamide gel process was used to prepare Li2O-Al2O3-SiO2 （LAS） glass-ceramic powders. The effects of ZrO2 addition on the crystallization and phase transformation process in LAS system were investigated by using differential thermal analysis （DTA）, X-ray powder diffractometry （XRD） and Fourier transform infrared spectroscopy （FTIR）. The activation energy decreases from 304.6 to 248.9kJ/mol and the frequency factor decreases from 2.49×10 11 to 5.56×108 min -1 as ZrO2 content changes from 0 to 4.0%（mass fraction）. During calcination from 800 to 1200℃, hexagonal β-quartz solid-solution first crystallizes and then gradually transforms into tetragonal β-spodumene solid-solution with increasing temperature. The stability of β-quartz solid-solution increases with more ZrO2 additions and a minor crystalline phase, tetragonal zirconia, also appears.
Key words: LAS glass-ceramic； crystallization； zirconia