Patent US4124667A successfully refreshed from Google Patents.
US4124667A
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Process for producing sintered silicon carbide ceramic body
Assignee: Stemcor Corp
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Filing: 1977-04-25
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Granted: 1978-11-07
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Expires: 1997-04-25
Abstract
Abstract Pressureless sintering of silicon carbide to produce ceramic bodies having 75% and greater theoretical densities, can be accomplished by firing shaped bodies, containing finely divided silicon carbide, boron source such as boron carbide, carbon source such as phenolic resin and a temporary binder, at a sintering temperature of from about 1900 DEG C to about 2500 DEG C.
Inventors
- 👤 John A. Coppola
- 👤 Laurence N. Hailey
- 👤 Carl H. McMurtry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:58
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
258 words
A process for producing a sintered ceramic body, comprising the steps of: (a) mixing together a raw batch comprising: (i) from about 91 to about 99.35 parts by weight alpha silicon carbide and having a surface area of from about 1 to about 100 m 2 /g; (ii) from about 0.67 to about 20 parts by weight of a carbonizable, organic solvent soluble, organic material having a char yield of from about 25 to about 75% by weight; (iii) from about 0.15 to about 5 parts by weight of a boron source containing from about 0.15 to about 3.0 parts by weight boron; and (iv) from about 5 to about 15 parts by weight of temporary binder; (b) adding to the raw batch from about 25 to about 100% by weight of the raw batch of an organic solvent in which the carbonizable, organic solvent soluble, organic material is soluble; (c) stirring the raw batch and organic solvent in such a way as to disperse the carbonizable, organic solvent soluble, organic material about the silicon carbide of the raw batch; (d) drying the stirred mixture in such a way as to evaporate the organic solvent from the mixture; (e) shaping the dried mixture in such a way as to produce a shaped body having a density of to least about 1.60 g/cc; (f) curing the temporary binder within the shaped body; and (g) firing the shaped body for such time, at such temperature and in such environment as to produce a density of at least about 2.40 g/cc.
Claim 2
Dependent Claim
258 words
A process for producing a sintered ceramic body, comprising the steps of: (a) mixing together a raw batch comprising: (i) from about 91 to about 99.35 parts by weight alpha silicon carbide and having a surface area of from about 1 to about 100 m 2 /g; (ii) from about 0.67 to about 20 parts by weight of a carbonizable, organic solvent soluble, organic material having a char yield of from about 25 to about 75% by weight; (iii) from about 0.15 to about 5 parts by weight of a boron source containing from about 0.15 to about 3.0 parts by weight boron; and (iv) from about 5 to about 15 parts by weight of temporary binder; (b) adding to the raw batch from about 25 to about 100% by weight of the raw batch of an organic solvent in which the carbonizable, organic solvent soluble, organic material is soluble; (c) stirring the raw batch and organic solvent in such a way as to disperse the carbonizable, organic solvent soluble, organic material about the silicon carbide of the raw batch; (d) drying the stirred mixture in such a way as to evaporate the organic solvent from the mixture; (e) shaping the dried mixture in such a way as to produce a shaped body having a density of to least about 1.60 g/cc; (f) curing the temporary binder within the shaped body; and (g) firing the shaped body for such time, at such temperature and in such environment as to produce a density of at least about 2.40 g/cc.
Claim 3
Dependent Claim
16 words
A process according to claim 1, wherein the stirring continues for at least about 5 minutes.
Claim 4
Dependent Claim
13 words
A process according to claim 2, wherein the stirring continues about 15 minutes.
Claim 5
Dependent Claim
12 words
A process according to claim 1, wherein the shaping is by extrusion.
Claim 6
Dependent Claim
22 words
A process according to claim 1, wherein the shaping is by compression at a pressure between about 4,000 and about 100,000 psi.
Claim 7
Dependent Claim
22 words
A process according to claim 5, wherein the shaping is by compression at a pressure between about 16,000 and about 20,000 psi.
Claim 8
Dependent Claim
40 words
A process according to claim 1, wherein the temporary binder is polyvinyl alcohol and the curing is accomplished by heating the shaped body at a temperature of about 90° to about 100° C for about 1 to about 2 hours.
Claim 9
Dependent Claim
35 words
A process according to claim 1, wherein the shaped body is fired for from about 20 to about 60 minutes; at a temperature of from about 1900° to about 2500° C; and in a vacuum.
Claim 10
Dependent Claim
61 words
A process according to claim 1, wherein the shaped body is fired for from about 20 to about 60 minutes; at a temperature of from about 1900° to about 2500° C; and in up to about 1 atmosphere of pressure of a gas selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, neon, nitrogen and mixtures thereof.
Claim 11
Dependent Claim
37 words
A process according to claim 9, wherein the gas is approximately 1 atmosphere of the member selected from the group consisting of argon, helium and neon; and the temperature is from about 2060° to about 2100° C.
Claim 12
Dependent Claim
26 words
A process according to claim 9, wherein the gas is about 1 atmosphere of nitrogen, and the temperature is from about 2260° to about 2300° C.
Claim 13
Dependent Claim
13 words
A process according to claim 1, wherein the shaping is by injection molding.
Claim 14
Dependent Claim
13 words
A process according to claim 1, wherein the shaping is by transfer molding.
Claim 15
Dependent Claim
12 words
A process according to claim 1, wherein the shaping is by casting.
Claim 16
Dependent Claim
13 words
A process according to claim 1, wherein the shaping is by cold pressing.
Claim 17
Dependent Claim
13 words
A process according to claim 1, wherein the shaping is by isostatic pressing.
Claim 18
Dependent Claim
257 words
A process for producing a sintered ceramic body, comprising the steps of: (a) mixing together a raw batch comprising: (i) from about 91 to about 99.35 parts by weight amorphous silicon carbide having a surface area of from about 1 to about 100 m 2 /g; (ii) from about 0.67 to about 20 parts by weight of a carbonizable, organic solvent soluble, organic material having a char yield of from about 25 to about 75% by weight; (iii) from about 0.15 to about 5 parts by weight of a boron source containing from about 0.15 to about 3.0 parts by weight boron; and (iv) from about 5 to about 15 parts by weight of temporary binder; (b) adding to the raw batch from about 25 to about 100% by weight of the raw batch of an organic solvent in which the carbonizable, organic solvent soluble, organic material is soluble; (c) stirring the raw batch and organic solvent in such a way as to disperse the carbonizable, organic solvent soluble, organic material about the silicon carbide of the raw batch; (d) drying the stirred mixture in such a way as to evaporate the organic solvent from the mixture; (e) shaping the dried mixture in such a way as to produce a shaped body having a density of at least about 1.60 g/cc; (f) curing the temporary binder within the shaped body; and (g) firing the shaped body for such time, at such temperature and in such environment as to produce a density of at least about 2.40 g/cc.
Claim 19
Dependent Claim
257 words
A process for producing a sintered ceramic body, comprising the steps of: (a) mixing together a raw batch comprising: (i) from about 91 to about 99.35 parts by weight amorphous silicon carbide having a surface area of from about 1 to about 100 m 2 /g; (ii) from about 0.67 to about 20 parts by weight of a carbonizable, organic solvent soluble, organic material having a char yield of from about 25 to about 75% by weight; (iii) from about 0.15 to about 5 parts by weight of a boron source containing from about 0.15 to about 3.0 parts by weight boron; and (iv) from about 5 to about 15 parts by weight of temporary binder; (b) adding to the raw batch from about 25 to about 100% by weight of the raw batch of an organic solvent in which the carbonizable, organic solvent soluble, organic material is soluble; (c) stirring the raw batch and organic solvent in such a way as to disperse the carbonizable, organic solvent soluble, organic material about the silicon carbide of the raw batch; (d) drying the stirred mixture in such a way as to evaporate the organic solvent from the mixture; (e) shaping the dried mixture in such a way as to produce a shaped body having a density of at least about 1.60 g/cc; (f) curing the temporary binder within the shaped body; and (g) firing the shaped body for such time, at such temperature and in such environment as to produce a density of at least about 2.40 g/cc.
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) | 1981-11-06 | 1982-05-08 | 1982-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-06 | 1986-05-08 | 1986-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-06 | 1990-05-08 | 1990-11-07 | $7700.00 | Window Closed / Lapsed |