Creep-resistant, high-strength silicon carbide fibers
US6069102A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1998 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | May 21, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B41/5346
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high strength, high creep resistant, boron-doped, silicon carbon fiber having no boron nitride coating, originally formed by sintering, is produced by exposing the fiber to a nitrogen atmosphere at a temperature equal to or preferably elevated above the sintering temperature and also exposing the fiber to a carbon monoxide-containing atmosphere at a temperature sufficient to remove boron and boron nitride. The nitrogen atmosphere step may be performed before or after the carbon monoxide-containing atmosphere step. The resulting, uncoated SiC fibers have tensile strengths greater than approximately 2.0 GPa and Morscher-DiCarlo BSR test creep resistance M values greater than approximately 0.75 at 1400 degrees C. for one hour in argon. The method is applicable to non-sintered fibers as well, in which case the nitrogen exposure is carried out at between approximately 1750 to 2250 degrees C. and the carbon monoxide exposure is carried out at between approximately 1600 to 2200 degrees C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.