Monolithic Alpha-Alumina Through Pressure Filtration of Seeded Boehmite Gels
Abstract
Research has shown that fully dense alpha-alumina of millimetre dimensions can be processed through sintering of seeded boehmite gels in the temperature range of 1300 to 1400 C. However, the processing of larger size samples has been hindered due to excessive cracking of the gels during drying. This problem is eliminated by densifying the gels first through pressure filtration prior to drying. Acid stabilised suspensions of boehmite seeded with alpha-alumina were gelled and pressure filtered by an expression method at a piston pressure of 3.5 MPa. In order to eliminate density gradients, samples were equilibrated at this pressure for at least 12 h to attain green densities of about 58%. Samples as large as 2.5 cm in diameter were sintered to densities higher than 99.4% TD at 1300 C without any cracking.
Recommended Citation
S. Sevinctav et al., "Monolithic Alpha-Alumina Through Pressure Filtration of Seeded Boehmite Gels," Third ECers. Proc. 3 rd European Ceramic Society Conf., vol. 1, pp. 687 - 690, Jan 1993.
Meeting Name
3 rd European Ceramic Society Conf.
Department(s)
Materials Science and Engineering
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Publication Date
1993-01-01
