# US 5,344,709 A · Silicon carbide fiber and method of manufacturing the same

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- Number: US 5,344,709 A
- Document ID: US5344709A
- Status: Granted
- Kind: A
- Application number: 07/884,058
- Filed: 1992-05-14
- Granted: 1994-09-06
- Earliest claimed: 1988-06-15
- Assignees: Nippon Carbon Co., Ltd.
- Inventors: Atsuya Tokutomi; Hiroshi Ichikawa; Kenji Ushikoshi; Hiroshi Yamauchi
- Web page: https://patentgrep.com/patent/US5344709A

## CPC

- C04B 35/571: obtained from {Si-containing} polymer precursors {or organosilicon monomers}
- C04B 41/4584: {Coating or impregnating of particulate or fibrous ceramic material (C04B20/10, C04B35/628 take precedence)}
- Y10T 428/2918: including free carbon or carbide or therewith [not as steel]
- Y10T 428/292: In coating or impregnation
- Y10T 428/2933: Coated or with bond, impregnation or core
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A silicon carbide fiber having low specific electric resistance and excellent mechanical properties and a method for manufacturing the fiber. The silicon carbide fiber is characterized in that an amorphous carbon film is formed on the surface thereof. The fiber is manufactured by heating an antimelt-treated polycarbosilane fiber at a temperature not exceeding 1000.degree. C. in an inert gas atmosphere followed by heating at a temperature of greater than 1000.degree. C. and up to 1500.degree. C. in an atmosphere of a mixture of hydrocarbon gas and inert gas.

## Claims

### Claim 1

A silicon carbide fiber having an amorphous carbon film formed on the surface thereof, said silicon carbide fiber obtained by heating an antimelt-treated polycarbosilane thread at a temperature not exceeding 1000.degree. C. in an atmosphere of inert gas and thereafter heating said thread at a temperature of above 1000.degree. C. and up to 1500.degree. C. in an atmosphere of hydrocarbon gas and inert gas wherein said hydrocarbon gas content is in the range of 0.01 to 50 vol. %, said silicon carbide fiber having a specific electric resistance of 10.sup.-1 -10.sup.1 .OMEGA..multidot.cm, a tensile strength of 200-350 kg/mm.sup.2 and a tensile modulus of 18-25 t/mm.sup.2.

### Claim 2 (depends on 1)

The silicon carbide fiber of claim 1, wherein the thickness of the amorphous carbon film is 1 nm to 1 .mu.m.