US4019913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for fabricating silicon carbide articles
Assignee: Saint Gobain Abrasives Inc
•
Filing: 1975-07-18
•
Granted: 1977-04-26
•
Expires: 1995-07-18
Abstract
Abstract Silicon carbide articles are formed by wet milling a mixture of silicon carbide having an average particle size less than 10 microns, and colloidal graphite; eliminating powder agglomerates larger than 325 mesh (U.S. Standard Sieve Series); drying the milled powder and pressing it to the desired shape; and finally, firing the preform at approximately 2000° C. in the presence of silicon, converting the graphite to silicon carbide.
Inventors
- 👤 Gerald Q. Weaver
- 👤 Bradford A. Olson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:33
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/573
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
114 words
A process for manufacturing a silicon carbide body which comprises the steps of preparing a fluid mixture of a liquid, fine silicon carbide powder having an average particle size less than 10 microns and colloidal graphite, said graphite being present in an amount of from 5 to 40% by weight of the total weight of graphite and silicon carbide, thoroughly mixing said silicon carbide and graphite, eliminating agglomerates of the powder having a size greater than 325 mesh, drying the powder, forming the dry powder to shape and thereafter firing the shaped body at a temperature in excess of 2000° C. in the presence of silicon to convert the colloidal graphite to silicon carbide.
Claim 2
Dependent Claim
114 words
A process for manufacturing a silicon carbide body which comprises the steps of preparing a fluid mixture of a liquid, fine silicon carbide powder having an average particle size less than 10 microns and colloidal graphite, said graphite being present in an amount of from 5 to 40% by weight of the total weight of graphite and silicon carbide, thoroughly mixing said silicon carbide and graphite, eliminating agglomerates of the powder having a size greater than 325 mesh, drying the powder, forming the dry powder to shape and thereafter firing the shaped body at a temperature in excess of 2000° C. in the presence of silicon to convert the colloidal graphite to silicon carbide.
Claim 3
Dependent Claim
24 words
The process of claim 1 wherein the mixture of silicon carbide and graphite is first milled in water and then in an organic medium.
Claim 4
Dependent Claim
33 words
The process of claim 1 wherein the pressed powder is fired to a temperature above 1900° C. imn an inert atmosphere to partially sinter the fine silicon carbide powder in the starting mixture.
Claim 5
Dependent Claim
26 words
The process of claim 3 including the step of further shaping of said partially sintered body prior to the final firing in the presence of silicon.
Claim 6
Dependent Claim
17 words
The process of claim 1 wherein said forming of said dry powder is accomplished by slip casting.
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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |