Process for improving the oxidative stability of a composite material having a fibrous reinforcement and a glass, glass-ceramic or ceramic matrix
US5695830A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1994 |
| Grant date | Dec 9, 1997 |
| Priority date | — |
| Expiry date | Jul 11, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/5248
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A reinforcing fiber of the non-oxide ceramic type or of carbon to be used in the manufacture of a composite material with a glass, glass-ceramic or ceramic matrix, which composite exhibits good oxidative stability, is treated using a process comprising the steps consisting of: if necessary, oxidizing the fiber superficially or depositing thereon a layer of the same composition but including oxygen; placing the fiber in a chemical vapor deposition vessel; carrying out a pre-treatment at a temperature of 850.degree. to 1250.degree. C., in the presence of hydrogen, at a pressure of 50 to 300 mbar; injecting a mixture of neutral carrier gas and ammonia; stopping the injection and adjusting the pressure to a value of 1 to 10 mbar; injecting AlCl.sub.3 in a neutral diluting gas; producing on the fiber a deposit of AlN by simultaneously injecting a mixture of AlCl.sub.3 and a neutral carrier gas, and a mixture of NH.sub.3 and a neutral carrier gas, until the desired thickness of AlN is obtained; after stopping injection, cooling with a stream of neutral gas; and recovering the fiber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.