A new explanation for the induction period observed during nucleation of lithium disilicate glass

A model is introduced to describe the effect of nucleation time and heating rate on the induction period observed during crystallization of glass. Nuclei formed during thermal treatment of a glass will grow with time. During further heating up, besides an accelerated crystal growth, also the critical nucleus of the crystalline phase increases. If during subsequent rapid heating, the crystals get smaller than the critical radius, they will be dissolved again. If the glass is kept only for a short time at nucleation temperature, all nuclei will be dissolved; however, if they are kept for a long time, an increasing quantity of nuclei will be large enough to survive the subsequent heating process. Numerical calculations using experimental data for the nucleation of lithium disilicate show that the induction period of the nucleation process can quantitatively be explained assuming steady state nucleation.