US3853635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making carbon-aluminum composites
Assignee: Pure Carbon Co Inc
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Filing: 1972-10-19
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Granted: 1974-12-10
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Expires: 1992-10-19
Abstract
Abstract A process for impregnating a mass of carbon particles with metal, preferably an aluminum alloy, to form a solid billet suitable for machining therefrom articles having advantageous durability and lubricity characteristics, particularly as apex seals for Wankel engines. A mass of carbon particles is heated to a temperature at or above the melting point of the metal in a closed crucible of permeable refractory material such as porous carbon, and the molten metal is poured over the porous crucible into a second crucible wherein the porous crucible becomes enveloped by the molten metal but the molten metal does not penetrate the porous crucible. The atmosphere surrounding the molten metal and porous crucible is then pressurized to force the molten metal through the porous crucible and thus cause controlled impregnation of the mass of particles.
Inventors
- 👤 J Demendi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:41
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B35/00; C04B35/515; C04B35/52; C04B41/45; C04B41/50; C04B41/51; C04B41/80; C04B41/81; C04B41/85; C04B41/88; F; F01; F01C; F01C19/00; F01C19/02; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12486
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
168 words
A PROCESS FOR IMPREGNATING A MASS OF CARBON PARTICLES WITH AN ALLOY OF ALUMINUM, SILICON AND AT LEAST ONE OTHER METAL COMPRISING THE STEPS OF MELTING A QUANTITY OF SAID ALLOY, PLACING A MASS OF CARBON PARTICLES IN A POROUS CRUCIBLE FORMED FROM A REFRACTORY MATERIAL, SAID PARTICLES BEING SMALLER THAN 40 MICRONS AND HAVING A POROSITY RANGE OF 30 TO 60 PERCENT BY VOLUME, THE POROSITY OF THE POROUS CRUCIBLE BEING AT LEAST 20 PERCENT BY VOLUME, PLACING THE POROUS CRUCIBLE IN AN IMPERMEABLE CRUCIBLE, POURING THE MOLTEN ALLOY OVER SAID POROUS CRUCIBLE AND INTO SAID IMPERMEABLE CRUCIBLE, EQUALIZING THE TEMPERATURE BETWEEN SAID MOLTEN ALLOY AND SAID CRUCIBLES, SUBJECTING SAID CRUCIBLES, CARBON PARTICLES AND MOLTEN ALLOY TO A GAS PRESSURE OF BETWEEN 2,000 PSI AND 4,500 PSI FOR FROM ONE TO FIVE MINUTES TO FORCE SAID MOLTEN ALLOY TO PENETRATE THE POROUS CRUCIBLE AND IMPREGNATE THE CARBON PARTICLES, RAPIDLY COOLING THE POROUS CRUCIBLE TO ROOM TEMPERATURE, AND THEN REMOVING THE THUS FORMED BILLET OF ALLOY-IMPREGNATED CARBON PARTICLES.
Claim 2
Dependent Claim
168 words
A PROCESS FOR IMPREGNATING A MASS OF CARBON PARTICLES WITH AN ALLOY OF ALUMINUM, SILICON AND AT LEAST ONE OTHER METAL COMPRISING THE STEPS OF MELTING A QUANTITY OF SAID ALLOY, PLACING A MASS OF CARBON PARTICLES IN A POROUS CRUCIBLE FORMED FROM A REFRACTORY MATERIAL, SAID PARTICLES BEING SMALLER THAN 40 MICRONS AND HAVING A POROSITY RANGE OF 30 TO 60 PERCENT BY VOLUME, THE POROSITY OF THE POROUS CRUCIBLE BEING AT LEAST 20 PERCENT BY VOLUME, PLACING THE POROUS CRUCIBLE IN AN IMPERMEABLE CRUCIBLE, POURING THE MOLTEN ALLOY OVER SAID POROUS CRUCIBLE AND INTO SAID IMPERMEABLE CRUCIBLE, EQUALIZING THE TEMPERATURE BETWEEN SAID MOLTEN ALLOY AND SAID CRUCIBLES, SUBJECTING SAID CRUCIBLES, CARBON PARTICLES AND MOLTEN ALLOY TO A GAS PRESSURE OF BETWEEN 2,000 PSI AND 4,500 PSI FOR FROM ONE TO FIVE MINUTES TO FORCE SAID MOLTEN ALLOY TO PENETRATE THE POROUS CRUCIBLE AND IMPREGNATE THE CARBON PARTICLES, RAPIDLY COOLING THE POROUS CRUCIBLE TO ROOM TEMPERATURE, AND THEN REMOVING THE THUS FORMED BILLET OF ALLOY-IMPREGNATED CARBON PARTICLES.
Claim 3
Dependent Claim
37 words
A process as defined in claim 1 wherein said metal comprises a hyper-eutectic aluminum-silicon alloy, said particles comprise calcined coconut shell char, and said alloy is at a temperature of about 1,100*F. when the pressure is applied.
Claim 4
Dependent Claim
43 words
A process as defined in claim 1 wherein the billet is annealed for from 6 to 10 hours at 900* to 1,000*F. and then further held for from 3 to 5 hours at 400* to 500*F. and then rapidly cooled to room temperature.
Claim 5
Dependent Claim
30 words
A process as defined in claim 1 wherein the porous crucible is made of a non-graphitized carbon and the billet is removed from the crucible by breaking away the crucible.
References Cited (Backward Citations)
US3239319A
Cited
US3523766A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |