Densification of alumina coated with a MgO-Al2O3-SiO2 (MAS) glass was investigated from 1400° to 1460°C. Spinel was observed to form at the liquid-alumina interface, whereas mullite crystallized uniformly in the liquid. Spinel and mullite crystallization kinetics were accelerated by smaller alumina particle size. Mullite and spinel crystallization retarded densification by forming a percolating network. Boron doping suppressed spinel formation, and thus alumina sintered to higher densities at low temperature. The concept of glass basicity is proposed as a useful guide for selecting dopants for low-temperature sintering.
|Original language||English (US)|
|Number of pages||10|
|Journal||Journal of the American Ceramic Society|
|State||Published - May 1998|
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry