Silicon carbide fibers with low boron content
US6022820A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1998 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | May 21, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/19
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Silicon carbide (SiC) fibers, or SiC bodies such as coatings, thin films, substrates or bulk objects, which have been sintered with boron containing additives to promote densification and pore removal, are further treated to remove a substantial amount of the residual boron from the SiC fibers. The SiC fibers, subsequent to the sintering steps and either before or after cooling, are exposed to a carbon monoxide (CO) containing atmosphere at elevated temperatures from approximately 1600-2200.degree. C., but more preferably from approximately 1700-2000.degree. C., with treatment times ranging from seconds to hours to days depending on the chosen treatment temperature. The resulting SiC fibers show a significant reduction of residual boron content, a reduction of greater than 90% in some cases, while retaining high tensile strength. Fibers with less than 0.1 wt % residual boron have been obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.