Role of TiO2 and ZrO2 on crystallizing phases and microstructure in Li, Ba aluminosilicate glass

Different concentrations of TiO2 and ZrO2 were incorporated in Li, Ba aluminosilicate glass to establish their effects on the crystallization process. The kinetics of phase transformations, the final crystalline phase assemblages and the microstructures formed were found to be dependent on the types and concentration of the nucleant involved. The presence of ZrO2 and TiO2 were found to enhance the crystallizability of the glass. ZrO2 is much better than TiO2 in promoting homogeneous nucleation and growth of extremely fine-grained microstructure of β-eucryptite ss and hexacelsian. ZrO2 retarded the formation of β-spodumene ss and monoclinic celsian. TiO2 in low concentrations greatly facilitates the crystallization process and favors the transformation of β-eucryptite ss → β-spodumene ss and hexacelsian → monoclinic celsian.