The effect of complex nucleating agent on the crystallization, phase formation and performances in lithium aluminum silicate (LAS) glasses

The glasses and glass-ceramics in Li2O-Al2O3-SiO2 system containing three complex nucleating agents (TiO2 + ZrO2 + P2O5) were prepared respectively. The effects of P2O5 content on crystallization mechanism and microstructure were researched by means of Differential Scanning Calorimetry, X-Ray Diffraction, Raman Spectra, Fourier Transform Infrared and Scanning Election Microscopy. Simultaneously, the effects of structure and composition on thermal expansion coefficient, transmittance, Vickers hardness, density, bending strength, and chemical stability were also discussed. The results indicated that P2O5 can promote the nucleation and crystallization process by forming AlPO4 and accelerating the precipitation of ZrTiO4. With the increase of P2O5 content (less 5 wt%), the promoting effect of elevated crystallization temperature on the process of grain grown enhanced gradually. Especially when P2O5 content is 5 wt%, the sample have the smallest crystals and the best performance, and there is a relatively low temperature and wide temperature range where could keep the grain size of P5 samples almost unchanged.