Densification controlled by solution‐precipitation during liquid‐phase sintering was analyzed for the aluminamagnesium aluminosilicate glass system. As a model system for liquid‐phase sintering, narrowly sized alumina powders and up to 20 vol% magnesium aluminosilicate glass samples were isothermally sintered at 1550° to 1650°C. Densification rate increases with increasing liquid content and sintering temperature but decreases with increasing density. For samples with >15% grain growth, the densification rate during the solution‐precipitation stage of sintering was proportional to (particle size)−2 and thus interface reaction‐controlled. Activation energies ranged from 270 to 500 kJ/mol over the relative density range of 66% to 96%, respectively. The low activation energy is attributed to densification by particle rearrangement, whereas the higher activation energy is due to densification controlled by interface‐reaction‐controlled solution‐precipitation. Intermediate activation energies are attributed to simultaneous densification by the two mechanisms.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of the American Ceramic Society|
|State||Published - Feb 1990|
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry