US3713816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing tungsten-silica cermets
Assignee: WR Grace and Co Conn
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Filing: 1970-04-02
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Granted: 1973-01-30
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Expires: 1990-04-02
Abstract
Abstract A process for preparing cermets of tungsten and silica by mixing a source of tungsten such as ammonium metatungstate or tungsten sol with a silica sol, passing the resulting mixture through a fluid energy mill and reducing the tungsten in the effluent of the mill with hydrogen. The product is then sintered in an inert atmosphere at a temperature in excess of 1,500* C.
Inventors
- 👤 Cragh A Mac
- 👤 A Patil
- 👤 G Ashby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:53
CPC Classifications
C; C22; C22C; C22C32/00; C22C32/001; C22C32/0015; C22C32/0031
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
122 words
A process for preparing cermets of tungsten and silica composed of particles having a particle size of less than 10 microns which comprises the steps of: a. admixing a source of tungsten selected from the group consisting of solutions of ammonium metatungstate and tungsten oxide sol with a silica sol. b. passing the resulting mixture through a fluid energy mill operated at an outlet temperature of 300*-400* C. c. converting the tungsten oxide in the mill effluent to the metal by heating to at least about 1,00* C in an atmosphere of hydrogen, d. sintering the resulting product in an atmosphere of an inert gas at a temperature of 1,500*-1,800* C for 2-8 hours, e. recovering the tungsten-silica cermet as a product.
Claim 2
Dependent Claim
122 words
A process for preparing cermets of tungsten and silica composed of particles having a particle size of less than 10 microns which comprises the steps of: a. admixing a source of tungsten selected from the group consisting of solutions of ammonium metatungstate and tungsten oxide sol with a silica sol. b. passing the resulting mixture through a fluid energy mill operated at an outlet temperature of 300*-400* C. c. converting the tungsten oxide in the mill effluent to the metal by heating to at least about 1,00* C in an atmosphere of hydrogen, d. sintering the resulting product in an atmosphere of an inert gas at a temperature of 1,500*-1,800* C for 2-8 hours, e. recovering the tungsten-silica cermet as a product.
Claim 3
Dependent Claim
21 words
The process according to claim 1 wherein the cermet contains from 1 to 99 weight percent silica, the balance being tungsten.
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |