Role of TiO_2 and ZrO_2 on crystallizing phases and microstructure in Li, Ba aluminosilicate glass

摘要

Different concentrations of TiO_2 and ZrO_2 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 ZrO_2 and TiO_2 were found to enhance the crystallizability of the glass ZrO_2 is much better than TiO_2 in promoting homogeneous nucleation and growth of extremely fine-grained microstructure of beta-eucryptite ss and hexacelsian. ZrO_2 retarded the formation of P-spodumene ss and monoclinic celsian. TiO_2 in low concentrations greatly facilitates the crystallization process and favors the transformation of beta-eucryptite ss -- > beta-spodumene ss and hexacelsian -- > monoclinic celsian.