Patent US4142008A successfully refreshed from Google Patents.
US4142008A
Expired / Lapsed
US
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Carbon filament coated with boron and method of making same
Assignee: Avco Corp
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Filing: 1977-06-27
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Granted: 1979-02-27
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Expires: 1997-06-27
Abstract
Abstract The invention is directed to a method of making a high strength-high modulus boron filament on a carbon substrate which is coated with pyrolytic graphite. Boron is deposited over the pyrolytic graphite. A preferred method of making such a filament citing specific pyrolytic graphite deposition temperatures is described.
Inventors
- 👤 Harold E. Debolt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:46
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/54; C23C16/545; C23C8/00; C23C8/06; C23C8/08; D; D01; D01F; D01F11/00; D01F11/10; D01F11/12; D01F11/124; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2916; Y10T428/2918; Y10T428/292
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
48 words
A method of forming high strength-high modulus boron filaments on a carbon substrate comprising: heating the carbon filament at a temperature in excess of about 2300° C. and depositing a layer of pyrolytic graphite on the substrate surface; and depositing a boron coating on said pyrolytic graphite coating.
Claim 2
Independent Claim
48 words
A method of forming high strength-high modulus boron filaments on a carbon substrate comprising: heating the carbon filament at a temperature in excess of about 2300° C. and depositing a layer of pyrolytic graphite on the substrate surface; and depositing a boron coating on said pyrolytic graphite coating.
Claim 3
Dependent Claim
47 words
A method as described in claim 1 wherein said pyrolytic graphite coating is formed by bringing a thermally decomposable material which releases and deposits carbon into contact with a carbon filament that has been heated to a graphitizing temperature above the thermal decomposition threshhold of said material.
Claim 4
Dependent Claim
16 words
A method as defined in claim 2 wherein the carbon filament temperature is about 2500° C.
Claim 5
Dependent Claim
14 words
A method as defined in claim 2 wherein the decomposable material is a hydrocarbon.
Claim 6
Dependent Claim
13 words
A method as defined in claim 2 wherein the decomposable material is methane.
Claim 7
Dependent Claim
19 words
A method as defined in claim 1 wherein the pyrolytic graphite coating has a minimum thickness of 0.02 mils.
References Cited (Backward Citations)
GB793730A
Cited
US3317338A
Cited
US3369920A
Cited
US3679475A
Cited
US3861953A
Cited
US3811940A
Cited
US3692565A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-26 | 1982-08-28 | 1983-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-26 | 1986-08-28 | 1987-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-26 | 1990-08-28 | 1991-02-27 | $7700.00 | Window Closed / Lapsed |