Glass in the yttria-alumina-silica system was synthesized using solgel techniques. Crystallization behavior of the gel and the glass was examined using variable heating rate data obtained by differential thermal analysis (DTA). The reaction rate constants for crystallization followed an Arrhenius temperature dependence, and the activation energies for crystallization were readily determined. Surface nucleation/crystallization dominated but no appreciable difference in crystallization between the gel and glass powders was evident. It was verified that, in this system, densification of the gel occurred before the onset of crystallization. Isothermal heat treatment of the gels and glasses produced 3Al2O3·2SiO2 and various polymorphs of Y2O3·2SiO2.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry