Abstract
A novel process for fabricating lightweight, cellular ceramics from sols is presented. The process utilizes the rapid viscosity change during gelation to stabilize the structure of a foamed silica sol. Manipulation of gel viscosity and foaming agent concentration resulted in a minimum cell size of 90 μm at 31% density and minimum density of 17% with average cell size of 400 μm. The flexural strength compared favorably with space shuttle tiles and sintered hollow glass spheres. From −50° to 150°C, the dielectric constant ranged from 1.51 to 1.55 for a 20% dense foam and was slightly dispersive, whereas the dielectric loss was comparable with fused silica.
Original language | English (US) |
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Pages (from-to) | 85-90 |
Number of pages | 6 |
Journal | Journal of the American Ceramic Society |
Volume | 73 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1990 |
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry