Microcellular Al2O3 Ceramics from Wood for Filter Applications |
| |
| Authors: | Carlos Renato Rambo Tarcisio Andrade Tobias Fey Heino Sieber Antônio Eduardo Martinelli Peter Greil |
| |
| Affiliation: | Materials Science and Engineering Graduate Program—PGMAT, Chemical Engineering Department—EQA, Federal University of Santa Catarina, 88040-900 Florianópolis, SC, Brazil;
Materials Science and Engineering Graduate Program—PPGCEM, UFRN—Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil;
Department of Materials Science, Glass and Ceramics, University of Erlangen-Nuremberg, D-91058 Erlangen, Germany |
| |
| Abstract: | Microcellular biomorphous Al2O3 was produced by Al-vapor infiltration in pyrolyzed rattan and pine wood-derived biocarbon preforms. At 1600°C the biocarbon preforms reacted with gaseous aluminum to form Al4C3. After oxidation in air at temperatures between 1550° and 1650°C, for 3 h, the biocarbon preforms were fully converted into α-Al2O3. Owing to the high anisotropy of biomorphous Al2O3, the compressive strength behavior was strongly dependent on the loading direction. The compressive strength of the specimens (0.1–11 MPa) is strongly dependent on their overall porosity and their behavior could be explained using the Gibson–Ashby model. The Darcian permeability ( k 1), as well as the non-Darcian permeability ( k 2), increased with an increase of the total porosity. The Darcian permeability of biomorphous Al2O3 was found to be in the range of 1–8 × 10−9 m2, which is in the order of magnitude of gas filters, and, therefore, suitable for several technological applications. |
| |
| Keywords: | |
|
|
