Effect Of Composition On Microstructural Development In Mg0-Al203-Si02 Glass-Ceramics

The transformation kinetics and microstructures of glass-ceramics, which deviate from those of a stoichiometric cordierite compound, are greatly dependent on the compositions of the starting glasses. Compositions richer in (Mg0, Si02) than the stoichiometric cordierite compound suppress the formation of , yet enhance the crystallization of a-cordierite, resulting in a higher content of a-cordierite. In contrast, compositions richer in Al203 than the stoichiometric cordierite compound have no effect on the crystallization of a-cordierite. Thus, most of the glass crystallises to u-cordierite in the initial stage, followed by the slow transformation of u-cordierite into an a-phase, which results in a low content of a-cordierite.