US4518702A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon carbide-boron carbide carbonaceous body
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1984-01-16
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Granted: 1985-05-21
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Expires: 2004-01-16
Abstract
Abstract The carbonaceous body of the invention is prepared by shaping and sintering a uniform powdery mixture composed of a powder of a low-temperature coke, a powder of boron carbide and a powder of silicon carbide in such a proportion that the weight proportion of the boron carbide and the silicon carbide is in the range from 2:98 to 80:20 and the volume proportion of the coke powder and the combination of the boron carbide and silicon carbide is in the range from 50:50 to 95:5. The carbonaceous body thus obtained is highly resistant against air oxidation even at a temperature of 1400 DEG C. in addition to the outstandingly high mechanical strengths in comparison with conventional carbonaceous shaped materials such as artificial graphite.
Inventors
- 👤 Hisayoshi Yoshida
- 👤 Ichitaro Ogawa
- 👤 Tsuyoshi Hagio
- 👤 Kazuo Kobayashi
- 👤 Takayoshi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:05
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/528
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
78 words
A carbonaceous shaped body which is a sintered body of a powdery mixture comprising a powder of a low-temperature coke and a combination of powders of boron carbide and silicon carbide, the weight proportion of the boron carbide and the silicon carbide being in the range from 2:98 to 80:20 and the volume proportion of the coke powder to the combination of the powders of boron carbide and silicon carbide being in the range from 50:50 to 95:5.
Claim 2
Dependent Claim
78 words
A carbonaceous shaped body which is a sintered body of a powdery mixture comprising a powder of a low-temperature coke and a combination of powders of boron carbide and silicon carbide, the weight proportion of the boron carbide and the silicon carbide being in the range from 2:98 to 80:20 and the volume proportion of the coke powder to the combination of the powders of boron carbide and silicon carbide being in the range from 50:50 to 95:5.
Claim 3
Dependent Claim
29 words
The carbonaceous shaped body as claimed in claim 1 wherein the weight proportion of the boron carbide to the silicon carbide is in the range from 2:98 to 50:50.
Claim 4
Dependent Claim
34 words
The method as claimed in claim 1 wherein the powdery mixture obtained in step (a) is mechanically ground prior to step (b) so as to have an average particle diameter smaller than 25 μm.
Claim 5
Independent Claim
132 words
A method for the preparation of a carbonaceous shaped body which comprises the steps of: (a) mixing together a powder of a low-temperature coke containing at least 4% by weight of a volatile matter, a powder of boron carbide and a powder of silicon carbide in such a proportion that the weight proportion of the boron carbide to the silicon carbide is in the range from 2:98 to 80:20 and the volume proportion of the coke powder to the combination of the boron carbide and the silicon carbide is in the range from 50:50 to 95:5 to form a uniform powdery mixture, (b) shaping the powdery mixture into a form, and (c) heating the shaped form of the powdery mixture at a temperature of 1000° C. or higher in an inert atmosphere.
Claim 6
Independent Claim
132 words
A method for the preparation of a carbonaceous shaped body which comprises the steps of: (a) mixing together a powder of a low-temperature coke containing at least 4% by weight of a volatile matter, a powder of boron carbide and a powder of silicon carbide in such a proportion that the weight proportion of the boron carbide to the silicon carbide is in the range from 2:98 to 80:20 and the volume proportion of the coke powder to the combination of the boron carbide and the silicon carbide is in the range from 50:50 to 95:5 to form a uniform powdery mixture, (b) shaping the powdery mixture into a form, and (c) heating the shaped form of the powdery mixture at a temperature of 1000° C. or higher in an inert atmosphere.
Claim 7
Dependent Claim
26 words
The shaped body of claim 1 wherein the powdery mixture from which the body is sintered contains at least 50% by weight of the coke powder.
Claim 8
Dependent Claim
22 words
The method of claim 4 wherein the powdery mixture prior to heating contains at least 50% by weight of the coke powder.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |