Method of making in-situ grown whisker reinforced ceramics
US5585314A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1995 |
| Grant date | Dec 17, 1996 |
| Priority date | — |
| Expiry date | Apr 18, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/80
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In-situ Si.sub.3 N.sub.4 whisker growth mechanisms have enhanced the microstructure of ceramic materials such as SiC through controlled growth of elongated beta-type Silicon Nitride grains. During liquid phase sintering at temperatures not exceeding 1850.degree. C., alpha-type Silicon Nitride dissolves into the liquid phase and reprecipitates as an elongated or acicular beta modification. The Si.sub.3 N.sub.4 reinforced microstructures can be formed by the controlled recrystallization of beta-type Silicon Nitride. In-situ whisker growth is enhanced or optimized through the use of thermal treatments and/or additions of seed materials. Finely divided beta-type Silicon Nitride particles which are insoluble in the liquid phase during sintering, and therefore have been used to provide nucleation sites for whisker growth are employed. Thermal treatments have been designed to promote directional growth (elongation) as opposed to development of less elongated type grains.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.