US4511666A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing beta'-silicon aluminum oxynitride (B'-SiAlON)
Assignee: Alcoa Corp
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Filing: 1982-12-16
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Granted: 1985-04-16
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Expires: 2002-12-16
Abstract
Abstract A process for producing a refractory material comprising essentially beta'-SiAlON wherein initial reactants comprising Al 2 O 3 and SiO 2 are nitrided for sufficient times and temperatures to convert at least a portion of the initial reactants to at least a portion of effective reactants and the effective reactants are then further heated to produce an essentially beta'-SiAlON refractory material.
Inventors
- 👤 Frankie E. Phelps
- 👤 Paul J. Boget
- 👤 Robert L. Troup
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:21
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/597; C01; C01B; C01B21/00; C01B21/082; C01B21/0821; C01B21/0826
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
A process for producing an essentially beta'-SiAlON refractory material, the process comprising: providing a uniform mixture of initial reactant materials as sources of SiO 2 , Al 2 O 3 and C in a reactor; nitriding said mixture at temperatures between 1200° C. and 1450° C. for a time sufficient to convert at least a portion of said initial reactants to at least a portion of effective reactants; and heating said effective reactants in the presence of nitrogen at temperatures from 1400° to 1650° C. for a time sufficient to convert said effective reactants to an essentially beta'-SiAlON refractory material.
Claim 2
Dependent Claim
100 words
A process for producing an essentially beta'-SiAlON refractory material, the process comprising: providing a uniform mixture of initial reactant materials as sources of SiO 2 , Al 2 O 3 and C in a reactor; nitriding said mixture at temperatures between 1200° C. and 1450° C. for a time sufficient to convert at least a portion of said initial reactants to at least a portion of effective reactants; and heating said effective reactants in the presence of nitrogen at temperatures from 1400° to 1650° C. for a time sufficient to convert said effective reactants to an essentially beta'-SiAlON refractory material.
Claim 3
Dependent Claim
24 words
The process according to claim 1 wherein heating said effective reactants in the presence of nitrogen is at temperatures from 1550° to 1600° C.
Claim 4
Dependent Claim
27 words
The process according to claim 1 wherein said SiO 4 initial reactant is selected from a group of materials consisting of quartz, cristabolite, tridymite and amorphous silica.
Claim 5
Dependent Claim
31 words
The process according to claim 1 wherein said Al 2 O 3 initial reactant is selected from a group of materials consisting of aluminum carbonate, aluminum nitrate, aluminum hydroxide and gibbsite.
Claim 6
Dependent Claim
93 words
The process according to claim 1 wherein said silicon dioxide and aluminum oxide initial reactants are selected from a group consisting of: clay having a ratio of aluminum oxide to silicon dioxide as defined by points along line AB of FIG. 1; a coked mixture of rice hulls and clay, the mixture having a ratio of aluminum oxide to silicon dioxide as defined by points along line AB of FIG. 1; and a precipitate having a ratio of aluminum oxide to silicon dioxide as defined by points along line AB of FIG. 1.
Claim 7
Dependent Claim
25 words
A process according to claim 1 wherein the preferred median particle size of the Al 2 O 3 initial reactant is less than 3.5 microns.
Claim 8
Dependent Claim
25 words
A process according to claim 1 wherein the preferred median particle size of the Al 2 O 3 initial reactant is less than 1 micron.
Claim 9
Dependent Claim
22 words
A process according to claim 1 wherein effective reactants are Si 3 N 4 , AlN and Al 2 O 3 .
Claim 10
Dependent Claim
25 words
A process according to claim 1 wherein said nitriding includes providing nitrogen under a pressure sufficient to maintain a flow of nitrogen through the reactor.
Claim 11
Dependent Claim
39 words
A process according to claim 1 whereby essentially beta'-SiAlON is produced continuously by providing the initial reactants to a reactor for nitriding and heating at a rate commensurate with the rate of discharge of said beta'-SiAlON from the reactor.
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) | 1988-04-15 | 1988-10-15 | 1989-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-15 | 1992-10-15 | 1993-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-15 | 1996-10-15 | 1997-04-16 | $7700.00 | Window Closed / Lapsed |