Method for preparing dense, pressureless sintered SiC whisker reinforced composite ceramics
US4946808A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1988 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Nov 10, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/77
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Whisker reinforced composites having improved strength and toughness are prepared by a process including densification by essentially pressureless sintering. There is no need to hot press or hot isostatic press to achieve a density of 99+% of theoretical for 10 vol. % whiskers and 93+% for 20 vol. % whiskers. The composites are derived from the desired volume fraction of whiskers, a sintering aid preferably submicron in average size range, and a major portion of a pressureless sinterable matrix material having an average particle size of not more than about 0.5 micron. Yttria-alumina composites are sintered at less than about 1800.degree. C. and for less than about two hours to avoid surface degradation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.