US4110386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon carbide sintered moldings and a method for producing said moldings
Assignee: Research Institute for Iron Steel and Other Metals of Tohoku University
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Filing: 1976-10-28
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Granted: 1978-08-29
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Expires: 1996-10-28
Abstract
Abstract Silicon carbide sintered moldings having a high flexural strength and various excellent properties are produced by mixing SiC powders with a binder of organosilicon low molecular weight compounds or organosilicon high molecular weight compounds, molding the mixture into a desired shape, heating the molding at a high temperature to form SiC sintered molding, impregnating the SiC sintered molding with the above described organosilicon compound and heating the impregnated SiC sintered molding, if necessary, said impregnation and heat treatment being repeated two or more times.
Inventors
- 👤 Seishi Yajima
- 👤 Josaburo Hayashi
- 👤 Mamoru Omori
- 👤 Masaaki Hamano
- 👤 Toetsu Shishido
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:17
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/575; C04B35/571
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
170 words
In a method for producing compact SiC sintered moldings, which comprises (a) mixing SiC powder with 0.3-30% by weight of binder consisting essentially of organosilicon high molecular weight compounds in which Si and C are main skeleton components and which are produced through polycondensation reaction of polysilane compounds having Si-Si bond, (b) molding the mixture under a pressure into a desired shape, and (c) heating the formed molding at a temperature of 800-2,200° C. under at least one atmosphere selected from the group consisting of vacuum, inert gas, CO gas and hydrogen gas to product an SiC sintered molding, the improvement which comprises subjecting said SiC sintered molding to at least one treatment which comprises impregnating the SiC sintered molding with said organosilicon high molecular weight compound used as the binder in step (a) above, and heat treating the resulting impregnated SiC sintered molding at a temperature of 700°-1,400° C. under at least one atmosphere selected from the group consisting of vacuum, an inert gas, CO gas and hydrogen gas.
Claim 2
Dependent Claim
170 words
In a method for producing compact SiC sintered moldings, which comprises (a) mixing SiC powder with 0.3-30% by weight of binder consisting essentially of organosilicon high molecular weight compounds in which Si and C are main skeleton components and which are produced through polycondensation reaction of polysilane compounds having Si-Si bond, (b) molding the mixture under a pressure into a desired shape, and (c) heating the formed molding at a temperature of 800-2,200° C. under at least one atmosphere selected from the group consisting of vacuum, inert gas, CO gas and hydrogen gas to product an SiC sintered molding, the improvement which comprises subjecting said SiC sintered molding to at least one treatment which comprises impregnating the SiC sintered molding with said organosilicon high molecular weight compound used as the binder in step (a) above, and heat treating the resulting impregnated SiC sintered molding at a temperature of 700°-1,400° C. under at least one atmosphere selected from the group consisting of vacuum, an inert gas, CO gas and hydrogen gas.
Claim 3
Dependent Claim
35 words
The method as claimed in claim 1, wherein the formed SiC sintered molding is heated at a temperature of 600°-1,700° C. under an oxidizing atmosphere to remove free carbon contained in the SiC sintered molding.
Claim 4
Dependent Claim
19 words
The method as claimed in claim 1, wherein said organosilicon low molecular weight compound is polysilanes having Si-Si bond.
Claim 5
Dependent Claim
13 words
The method as claimed in claim 1, wherein said polysilane is polydimethyl silane.
Claim 6
Dependent Claim
74 words
The method as claimed in claim 1, wherein SiC powders are prepared by preliminarily heating organosilicon high molecular weight compounds, in which Si and C are main skeleton components and which have been produced through polycondensation reaction of the organosilicon lower molecular weight compounds, at a temperature of 200°-1,500° C. in a non-oxidizing atmosphere under vacuum, atmospheric pressure or pressure to form SiC primary product, and pulverizing the primary product to form SiC powders.
Claim 7
Dependent Claim
55 words
The method as claimed in claim 5, wherein after the preliminarily heating for production of the primary product, the primary product is heated at a temperature of 1,000°-2,200° C. under at least one of atmospheres of vacuum, inert gases, CO gas and hydrogen gas to form fired product and then the pulverizing step is effected.
Claim 8
Dependent Claim
17 words
The method as claimed in claim 1, wherein said binder is polycarbosilane having the formula ##STR13## .
Claim 9
Dependent Claim
20 words
The method as claimed in claim 1, wherein SiC powders have an average grain size of less than 100 μm.
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) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |