Effect of Y-2O_3 on the crystallization kinetics of TiO_2 nucleated LAS glass for the production of nanocrystalline transparent glass ceramics

摘要

Crystallization kinetics of metastable |3-quartz solid solution as a desirable phase for the production of transparent lithium aluminosilicate (LAS) glass ceramics was investigated in the presence of Y2O3. Accordingly, differential thermal analysis scans were performed thoroughly to study the mechanism of crystallization kinetics. The aim of this investigation is to discover the complicated mechanism of crystallization process in the presence of co-additives and accordingly find a way for increasing the transparency of glass ceramics. It is shown that the bulk (3D) growth is intensively increased by the enhancement of Y_2O_3. Then again, reducing nucleation and increasing growth mechanisms were recognized for the LAS system in the presence of Y_2O_3. Results of the investigation illustrate that when co-additives are added to glasses, it is necessary to nucleate the optical component separately before the growth process.