Abstract
Mixtures of 95 vol% ultrafine γ-Al2O3 powder and 5 vol% ultrafine SiC powder, with average particle size of 40 nm, were mixed wet-ball milling and prepared by drying their slurry with a supercritical drying method and a microwave drying method. Al2O3 specimens dispersed with ultrafine-SiC particles as the secondary phase were hot-pressed, their powders being prepared by both the above drying methods. Difference between the superitical drying and the microwave drying method on the microstructure of Al2O3/5 vol%SiC composites was investigated. Dense Al2O3/SiC composites were obtained at lower hot-pressing temperatures when the mixture was prepared by supercritical drying method. Influence of the drying method on the γ- to α-Al2O3 transition behavior was also examined. Al2O3/SiC powder dried by the supercritical drying method showed narrow particle size distribution and the formation of soft agglomerates. Al2O3/SiC composite sintered by hot-pressing the powder dried with the supercritical drying method indicated relatively higher strength, whereas the strength of Al2O3/SiC composite through microwave drying method was low and had the large scatter.
Original language | English |
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Pages (from-to) | 460-464 |
Number of pages | 5 |
Journal | Journal of the Ceramic Society of Japan |
Volume | 107 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1999 |
Keywords
- Microstructure
- Microwave drying
- Supercritical drying
- Ultrafine SiC
ASJC Scopus subject areas
- Ceramics and Composites
- Chemistry(all)
- Condensed Matter Physics
- Materials Chemistry