The crystallization and microstructure evolution of lithium disilicate-based glass-ceramic

In the former glass, a small amount of spherical Li2Si2O5 crystals precipitated at the usual nucleation temperature, which changed little in size and packing density with the increase of the temperature. These spherical Li2Si2O5 also have no effect on the volume crystallization of residual glass or the morphology of subsequently formed plate-like Li2Si2O5 crystals. In the latter glass, Li2SiO3 crystallized first and then decomposed at higher temperature, forming two kinds of Li2Si2O5 crystals with different morphologies. The interlocked rod-like shaped Li2Si2O5 crystals were resulted from interaction of Li+ ions and SiO2-rich glassy phase and oriented crystal bundles of Li2Si2O5 were formed from rearrangement of a silicate framework in Li2SiO3.