US4472454A
Expired / Lapsed
US
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Process for the densification of a porous structure
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1982-11-24
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Granted: 1984-09-18
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Expires: 2002-11-24
Abstract
Abstract A process is disclosed for the densification of a porous structure. The structure is immersed in a liquid hydrocarbon and is heated by induction so as to form, by decomposition of the hydrocarbon, carbon or pyrolytic graphite which can be deposited in the pores or cavities of the structure. The process may be used for the densification of fabrics or felts for use in pads in disc brakes.
Inventors
- 👤 Michel Houdayer
- 👤 Jean Spitz
- 👤 Danh Tran-Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:39
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/521; C04B35/71; C04B35/78; C04B35/80; C04B35/83; C04B41/00; C04B41/45; C04B41/50; C04B41/5001; D; D01; D01F; D01F11/00; D01F11/10; D01F11/12; D01F11/121; D01F11/125; D01F11/14; D01F9/00; D01F9/08; D01F9/12; D01F9/127; F; F16; F16D; F16D69/00; F16D69/02; F16D69/023
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
A process for the densification of a porous structure having pores or cavities into which carbon or pyrolytic graphite may be introduced to increase the density of the structure comprising the steps of immersing the porous structure in a liquid hydrocarbon, heating the immersed structure and liquid hydrocarbon with induction heating, and, while the structure is immersed in the liquid hydrocarbon, vaporizing liquid hydrocarbon so that the immersed structure is substantially surrounded by a vapor film of vaporized liquid hydrocarbon and directly decomposing vaporized liquid hydrocarbon in a single continuous step so as to form, by decomposition of the hydrocarbon, carbon or pyrolytic graphite which is deposited in the pores or cavities of the structure.
Claim 2
Dependent Claim
115 words
A process for the densification of a porous structure having pores or cavities into which carbon or pyrolytic graphite may be introduced to increase the density of the structure comprising the steps of immersing the porous structure in a liquid hydrocarbon, heating the immersed structure and liquid hydrocarbon with induction heating, and, while the structure is immersed in the liquid hydrocarbon, vaporizing liquid hydrocarbon so that the immersed structure is substantially surrounded by a vapor film of vaporized liquid hydrocarbon and directly decomposing vaporized liquid hydrocarbon in a single continuous step so as to form, by decomposition of the hydrocarbon, carbon or pyrolytic graphite which is deposited in the pores or cavities of the structure.
Claim 3
Dependent Claim
16 words
A densification process according to claim 1, wherein the porous structure is of carbon or graphite.
Claim 4
Dependent Claim
20 words
A densification process according to claims 1 or 2, wherein heating takes place to temperatures between 1000° to 1300° C.
Claim 5
Dependent Claim
15 words
A densification process according to claims 1 or 2, wherein the liquid hydrocarbon is cyclohexane.
Claim 6
Dependent Claim
19 words
A densification process according to claim 1 or 2 wherein said pore structure is a fabric or a felt.
Claim 7
Dependent Claim
23 words
A densification process according to claim 1, wherein said liquid hydrocarbon is present only as liquid and vapor phases prior to decomposition thereof.
Claim 8
Dependent Claim
111 words
A process for the densification of a porous structure having pores or cavities in which carbon or pyrolytic graphite may be deposited to increase the density of the structure comprising the steps of immersing the porous structure in a liquid hydrocarbon which is to be decomposed to provide the carbon or pyrolytic graphite for densification of the porous structure, heating the immersed structure and liquid hydrocarbon with induction heating to vaporize liquid hydrocarbon and directly decompose vaporized liquid hydrocarbon to form carbon or pyrolytic graphite which is deposited in the pores and cavities of the porous structure in a single continuous step while the structure is immersed in the liquid hydrocarbon.
Claim 9
Dependent Claim
111 words
A process for the densification of a porous structure having pores or cavities in which carbon or pyrolytic graphite may be deposited to increase the density of the structure comprising the steps of immersing the porous structure in a liquid hydrocarbon which is to be decomposed to provide the carbon or pyrolytic graphite for densification of the porous structure, heating the immersed structure and liquid hydrocarbon with induction heating to vaporize liquid hydrocarbon and directly decompose vaporized liquid hydrocarbon to form carbon or pyrolytic graphite which is deposited in the pores and cavities of the porous structure in a single continuous step while the structure is immersed in the liquid hydrocarbon.
Claim 10
Dependent Claim
21 words
A densification process according to claim 7 wherein said porous structure is a fabric or a felt of carbon or graphite.
Claim 11
Dependent Claim
23 words
A densification process according to claim 7, wherein said liquid hydrocarbon is present only as liquid and vapor phases prior to decomposition thereof.
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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) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |