Effect of nucleation temperatures and time on crystallization behavior and properties of Li2O–Al2O3–SiO2 glasses

The crystallization behavior of Li2O–Al2O3–SiO2 glasses samples nucleated at different temperature and time (745 °C/2 h, 745 °C/6 h and 760 °C/6 h) was investigated by DTA, XRD and SEM. After nucleated at 745 °C for 2 and 6 h, the Avrami constants for the glass samples were 3.5–3.6 and activation energies of crystal growth were 276 ± 3 and 280 ± 5 kJ mol−1. The Avrami constant was 2.8 and activation energy of crystal growth was 302 ± 6 kJ mol−1 for samples nucleated at 760 °C for 6 h. The crystallized phase was identified as h-quartz solid solution and SEM observations indicated that glass–ceramic samples have fine grained microstructure which indicates bulk crystallization. With increasing nucleation temperature to 760 °C, the grain size increased and the values of flexural strength, hardness and fracture toughness decreased.