Claims
- 1. Thermally stable, nitrogen-free silicon carbide fibers having at least 75% crystallinity which contain at least about 0.2 weight boron and which have a density of at least about 2.9 gm/cm.sup.3 and an average tensile strength of at least about 164 ksi after heat treatment to a temperature of greater than about 1600.degree. C.
- 2. The fibers of claim 1 in which said fibers have a diameter of less than about 50 micrometers.
- 3. The fibers of claim 1 in which said fibers have a grain size of less than about 0.2 micrometers.
- 4. The fibers of claim 1 which have an oxygen content less than about 0.5 weight percent.
- 5. The fibers of claim 1 which have an oxygen content less than about 0.2 weight percent.
- 6. The fibers of claim 1 in which said fibers have an average grain size of less than about 0.5 micrometers.
Parent Case Info
This is a continuation of copending application Ser. No. 07/471,997 filed on Jan. 16, 1990, now U.S. Pat. No. 5,071,600.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
471997 |
Jan 1990 |
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