US5279737A
Expired / Lapsed
US
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Process for producing a porous ceramic and porous ceramic composite structure utilizing combustion synthesis
Assignee: University of Cincinnati
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Filing: 1993-06-03
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Granted: 1994-01-18
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Expires: 2013-06-03
Abstract
Abstract A process for producing a porous ceramic, ceramic composite or metal-ceramic composite structure by combustion synthesis wherein a foamed polymer shape is impregnated with a slurry of ceramic precursors and ignited to initiate combustion synthesis, thereby obtaining a ceramic, ceramic composite or metal-ceramic composite article having interconnected porosity. Ceramic composite filters having improved strength, toughness and thermal shock resistance are provided, with the ceramic composite being an oxide and a nonoxide.
Inventors
- 👤 Jainagesh A. Sekhar
- 👤 Sarit B. Bhaduri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:38
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2027; B01D39/2051; B01D39/2068; B01D39/2093; B22; B22C; B22C9/00; B22C9/08; B22C9/086; C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/65; C04B35/651; C04B38/00; C04B38/0022; C22; C22C; C22C1/00; C22C1/04; C22C1/05; C22C1/051; C22C1/053; C04B2111/00; C04B2111/00474; C04B2111/00793; C04B2111/0087
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
70 words
A process for producing a porous ceramic or ceramic composite structure, which comprises providing a slurry of particulate ceramic precursors capable of undergoing combustion synthesis, impregnating a foamed polymer shape with said slurry, heating the slurry-impregnated polymer shape to a temperature sufficient to remove said polymer, and igniting said ceramic precursors to initiate combustion synthesis, thereby obtaining a ceramic or ceramic composite structure having interconnected porosity and controlled pore size.
Claim 2
Dependent Claim
70 words
A process for producing a porous ceramic or ceramic composite structure, which comprises providing a slurry of particulate ceramic precursors capable of undergoing combustion synthesis, impregnating a foamed polymer shape with said slurry, heating the slurry-impregnated polymer shape to a temperature sufficient to remove said polymer, and igniting said ceramic precursors to initiate combustion synthesis, thereby obtaining a ceramic or ceramic composite structure having interconnected porosity and controlled pore size.
Claim 3
Dependent Claim
70 words
A process for producing a porous metal-ceramic composite structure, which comprises providing a slurry of particulate ceramic and metal precursors capable of undergoing combustion synthesis, impregnating a foamed polymer shape with said slurry, heating the slurry-impregnated polymer shape to a temperature sufficient to remove said polymer, and igniting said ceramic and metal precursors to initiate combustion synthesis, thereby obtaining a metal-ceramic composite structure having interconnected porosity and controlled pore size.
Claim 4
Dependent Claim
70 words
A process for producing a porous metal-ceramic composite structure, which comprises providing a slurry of particulate ceramic and metal precursors capable of undergoing combustion synthesis, impregnating a foamed polymer shape with said slurry, heating the slurry-impregnated polymer shape to a temperature sufficient to remove said polymer, and igniting said ceramic and metal precursors to initiate combustion synthesis, thereby obtaining a metal-ceramic composite structure having interconnected porosity and controlled pore size.
Claim 5
Dependent Claim
22 words
The process of claim 1 or 2, wherein said slurry contains at least one of suspension agents, binders, surfactants and anti-foaming agents.
Claim 6
Dependent Claim
30 words
The process of claim 1 or 2, wherein the step of impregnating said foamed polymer shape comprises repeated dipping of said polymer shape into said slurry and drying said slurry.
Claim 7
Dependent Claim
40 words
The process of claim 1 or 2, including the step of dipping said slurry impregnated polymer shape into said slurry at least once after the step of heating said slurry-impregnated polymer shape to a temperature sufficient to remove said polymer.
Claim 8
Dependent Claim
32 words
The process of claim 1 or 2, wherein said slurry-impregnated polymer shape is heated to a temperature of about 400° to about 1100° C. in order to volatilize or decompose said polymer.
Claim 9
Dependent Claim
40 words
The process of claim 1 or 2, including the step of applying a second slurry to said slurry-impregnated polymer shape, said second slurry containing particulate ceramic precursors capable of undergoing combustion synthesis and which will provide phases having desired properties.
Claim 10
Dependent Claim
105 words
The process of claim 1, wherein said ceramic or ceramic composite is chosen from the group consisting of borides of titanium, zirconium, niobium, tantalum, molybdenum, hafnium, chromium, and vanadium; carbides of titanium, hafnium, boron, aluminum, tantalum, silicon, tungsten, zirconium, niobium, and chromium; carbonitrides of titanium, niobium, and tantalum; nitrides of titanium, zirconium, boron, aluminum, silicon, tantalum, hafnium, and niobium; silicides of molybdenum, titanium, zirconium, niobium, tantalum, tungsten and vanadium; hydrides of titanium, zirconium, and niobium; aluminum oxide-titanium boride; titanium carbide-titanium boride; aluminum oxide-titanium boride-titanium nitride; aluminum oxide-titanium boride-titanium carbide; boron carbide-aluminum oxide; molybdenum silicide-aluminum oxide; molybdenum boride-aluminum oxide; chromium carbide-aluminum oxide; and vanadium nitride-aluminum oxide.
Claim 11
Dependent Claim
24 words
The process of claim 2, wherein said metal-ceramic composite is chosen from the group consisting of iron-aluminum oxide; aluminum-aluminum oxide-titanium boride; and titanium-titanium boride.
Claim 12
Dependent Claim
49 words
The process of claim 1 or 8, wherein said ceramic precursors comprise a mixture of from about 65% to about 95% by weight titanium and about 5% to about 35% by weight boron, said titanium and boron having average particle sizes ranging from about 1 to about 150 microns.
Claim 13
Dependent Claim
29 words
The process of claim 10, wherein said porous ceramic structure is a filter for molten metal, and wherein said ceramic precursors include additives for grain refining of said metal.
Claim 14
Dependent Claim
37 words
The process of claim 2 or 9, wherein said ceramic precursors comprise a mixture of iron oxide and metallic aluminum in approximately stoichiometric proportions and having average particle sizes ranging from about 1 to about 150 microns.
Claim 15
Dependent Claim
44 words
The process of claim 1, 2, 8 or 9, wherein said ceramic precursors comprise a mixture of about 35% to about 55% by weight aluminum, about 25% to about 35% by weight titanium dioxide, and about 20% to about 30% by weight boric oxide.
Claim 16
Dependent Claim
34 words
The process of claim 1 or 8, wherein said ceramic precursors comprise a mixture of from about 65% to about 75% by weight silicon and from about 25% to about 35% by weight graphite.
Claim 17
Dependent Claim
47 words
The process of claim 1, wherein said ceramic precursors comprise a mixture of from about 20% to about 30% aluminum, about 20% to about 25% titanium dioxide, about 15% to about 25% boric oxide, and about 25% to about 35% zirconium oxide, all percentages being by weight.
Claim 18
Dependent Claim
49 words
The process of claim 1 or 2, wherein said ceramic precursors comprise a mixture of from about 20% to about 30% aluminum, about 20% to about 25% titanium dioxide, about 15% to about 25% boric oxide, and about 25% to about 35% powdered niobium, all percentages being by weight.
Claim 19
Dependent Claim
54 words
The process of claim 1, wherein said ceramic precursors comprise a mixture of from about 20% to about 30% aluminum, about 20% to about 25% titanium dioxide, about 15% to about 25% boric oxide, about 20% to about 25% aluminum oxide, and about 3% to about 10% zirconium oxide, all percentages being by weight.
Claim 20
Dependent Claim
23 words
A porous metal-ceramic composite filter having interconnected porosity and controlled pore size made in accordance with the process of claim 2 or 9.
Claim 21
Dependent Claim
23 words
A porous ceramic composite filter having interconnected porosity and controlled pore size made in accordance with the process of claim 1 or 8.
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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) | 1997-01-17 | 1997-07-19 | 1998-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-17 | 2001-07-19 | 2002-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-17 | 2005-07-19 | 2006-01-18 | $7700.00 | Window Closed / Lapsed |