Patent US4624808A successfully refreshed from Google Patents.
US4624808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Forming a ceramic by flocculation and centrifugal casting
Assignee: Boeing North American Inc
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Filing: 1984-05-15
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Granted: 1986-11-25
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Expires: 2004-05-15
Abstract
Abstract A ceramic is fabricated by dispersing ceramic particles in a liquid, sedimenting the dispersion to remove large particles, and then changing its pH to flocculate the dispersed particles. The size distribution of the particles in each individual floc is similar to the size distribution of particles throughout the dispersion. The supernate is removed and the flocs are cast by centrifuging them into a mold. The cast flocs are dried and sintered to form the ceramic. To provide a multiphase ceramic, particles of two or more ceramics can be mixed together and flocced prior to centrifuging.
Inventors
- 👤 Frederick F. Lange
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:31
CPC Classifications
B; B28; B28B; B28B1/00; B28B1/20; C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/119; C04B35/515; C04B35/58; C04B35/584; C04B35/622
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
62 words
A method of fabricating a structural ceramic comprising the steps of: dispersing ceramic particles in a liquid; sedimenting the disposed particles to remove large particles and agglomerates; flocculating the dispersed ceramic particles; removing the clear supernate from the flocced ceramic particles; centrifuging said flocced ceramic particles to produce a consolidated mass capable of retaining its shape; and sintering the centrifuged ceramic particles.
Claim 2
Independent Claim
62 words
A method of fabricating a structural ceramic comprising the steps of: dispersing ceramic particles in a liquid; sedimenting the disposed particles to remove large particles and agglomerates; flocculating the dispersed ceramic particles; removing the clear supernate from the flocced ceramic particles; centrifuging said flocced ceramic particles to produce a consolidated mass capable of retaining its shape; and sintering the centrifuged ceramic particles.
Claim 3
Dependent Claim
22 words
The method as claimed in claim 1 wherein said step of centrifuging comprises centrifugally casting said flocced ceramic particles into a mold.
Claim 4
Dependent Claim
20 words
The method as claimed in claim 1 including the step of air drying said centrifuged ceramic particles prior to sintering.
Claim 5
Dependent Claim
19 words
The method as claimed in claim 1 wherein said step of flocculating comprises changing the pH of said liquid.
Claim 6
Independent Claim
71 words
A method of fabricating a structural ceramic comprising the steps of: dispersing ceramic particles in a liquid; sedimenting said dispersed particles to remove large particles and agglomerates; flocculating said dispersed particles by changing the pH of said liquid; removing supernate from said flocced particles; centrifugally casting said flocced particles into a mold to produce a consolidated mass capable of retaining its shape; drying said cast particles; and sintering said dried particles.
Claim 7
Independent Claim
71 words
A method of fabricating a structural ceramic comprising the steps of: dispersing ceramic particles in a liquid; sedimenting said dispersed particles to remove large particles and agglomerates; flocculating said dispersed particles by changing the pH of said liquid; removing supernate from said flocced particles; centrifugally casting said flocced particles into a mold to produce a consolidated mass capable of retaining its shape; drying said cast particles; and sintering said dried particles.
Claim 8
Independent Claim
116 words
A method of fabricating a multiphase structural ceramic comprising the steps of: dispersing particles of a first ceramic in a first liquid; sedimenting said dispersed particles of a first ceramic to remove large particles and agglomerates; flocculating the dispersed particles of said first ceramic; dispersing particles of a second ceramic in a second liquid; sedimenting said dispersed particles of a second ceramic to remove large particles and agglomerates; flocculating the dispersed particles of said second ceramic; removing clear supernate and mixing the flocced particles of said first and said second ceramics; centrifuging the mixture of said first and said second ceramics to produce a consolidated mass capable of retaining its shape; and sintering the centrifuged mixture.
Claim 9
Independent Claim
116 words
A method of fabricating a multiphase structural ceramic comprising the steps of: dispersing particles of a first ceramic in a first liquid; sedimenting said dispersed particles of a first ceramic to remove large particles and agglomerates; flocculating the dispersed particles of said first ceramic; dispersing particles of a second ceramic in a second liquid; sedimenting said dispersed particles of a second ceramic to remove large particles and agglomerates; flocculating the dispersed particles of said second ceramic; removing clear supernate and mixing the flocced particles of said first and said second ceramics; centrifuging the mixture of said first and said second ceramics to produce a consolidated mass capable of retaining its shape; and sintering the centrifuged mixture.
Claim 10
Dependent Claim
33 words
The method as claimed in claim 6 wherein said step of mixing comprises shaking the flocced particles of said first and said second ceramics together and then feeding the mixture into an homogenizer.
Claim 11
Dependent Claim
33 words
The method as claimed in claim 6 wherein said step of mixing comprises shaking the flocced particles of said first and said second ceramics together and then exposing the mixture to ultrasonic agitation.
Claim 12
Dependent Claim
19 words
The method as claimed in claim 6 including the step of air drying said centrifuged mixture prior to sintering.
Claim 13
Independent Claim
117 words
A method of fabricating a multiphase structural ceramic comprising the steps of: dispersing particles of a first ceramic in a first liquid; sedimenting said dispersed particles of a first ceramic to remove large particles and agglomerates; dispersing particles of a second ceramic in a second liquid; sedimenting said dispersed particles of a second ceramic to remove large particles and agglomerates; mixing the dispersed particles of said first and second ceramics; flocculating the particles of said first and second ceramics; removing clear supernate from said flocced particles; centrifuging the flocced particles of said first and second ceramics to produce a consolidated mass capable of retaining its shape; and sintering the centrifuged particles of said first and second ceramics.
Claim 14
Independent Claim
117 words
A method of fabricating a multiphase structural ceramic comprising the steps of: dispersing particles of a first ceramic in a first liquid; sedimenting said dispersed particles of a first ceramic to remove large particles and agglomerates; dispersing particles of a second ceramic in a second liquid; sedimenting said dispersed particles of a second ceramic to remove large particles and agglomerates; mixing the dispersed particles of said first and second ceramics; flocculating the particles of said first and second ceramics; removing clear supernate from said flocced particles; centrifuging the flocced particles of said first and second ceramics to produce a consolidated mass capable of retaining its shape; and sintering the centrifuged particles of said first and second ceramics.
Claim 15
Dependent Claim
46 words
The method as claimed in claim 10 including the steps of: flocculating the dispersed particles of said first ceramic and then redispersing them prior to said mixing step; and flocculating the dispersed particles of said second ceramic and then redispersing them prior to said mixing step.
Claim 16
Dependent Claim
20 words
The method as claimed in claim 10 including the step of drying said centrifuged particles prior to said sintering step.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |