Microstructural control of MgO–Al₂O₃–SiO₂ glass-ceramics using titanium oxides with varying particle sizes and crystallinities as nucleation agents

Abstract

Microstructural control of MgO–Al₂O₃–SiO₂ (MAS) glass-ceramic (GC) with precipitated enstatite (MgSiO₃) in the 0.68–12 µm range from a parent glass having one composition was achieved by using titanium oxides with varying particle sizes and crystallinities as nucleation agents. Specifically, compared with the MAS-GC prepared using TiO₂ with 50–200 nm and relative high crystallinity (TiO₂-L-H), the MAS-GC prepared by mixing TiO₂-L-H with TiO₂ having single nanometer size and relative low crystallinity displayed an increase in the average crystal particle size from 6.0 to 12 µm with the preservation of volume fraction. In addition, compared with the MAS-GC prepared using TiO₂-L-H, the MAS-GC prepared by TiO₂ having single nanometer size and relative high crystallinity exhibited a decrease in the average size of crystal particle from 6.0 to 0. 68 µm with a decrease in the volume fraction from 76 to 67 %. Therefore, these results indicated that the particle size and crystallinity of the raw glass materials are key parameters for controlling the microstructure of GCs.