US4190439A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of fine grain metal carbide powders and sintered articles therefrom
Assignee: AVOCET TUNSTEN Inc
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Filing: 1975-10-21
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Granted: 1980-02-26
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Expires: 1995-10-21
Abstract
Abstract Fine grain metal carbide powders are conveniently prepared from the corresponding metal oxide by heating in an atmosphere of methane in hydrogen. Sintered articles having a density approaching the theoretical density of the metal carbide itself can be fabricated from the powders by cold pressing, hot pressing or other techniques.
Inventors
- 👤 Frank P. Gortsema
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:12
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/645; C01; C01B; C01B13/00; C01B13/14; C01B13/18; C01B32/00; C01B32/90; C01B32/914; C04B35/515; C04B35/56; C22; C22C; C22C1/00; C22C1/04; C22C1/05; C22C1/051; C22C1/053; C22C1/056; C01P; C01P2002/00; C01P2002/70; C01P2002/77; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/60; C01P2004/61; C01P2004/62; C01P2006/00; C01P2006/10; C01P2006/12; C01P2006/60
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
A process for producing sintered metal carbide articles which comprises the steps of: (a) impregnating a carbohydrate material with a compound of a metal; (b) igniting the impregnated material product of step (a) to produce fragile agglomerates of sub-micron size metal oxide particles; (c) comminuting the metal oxide product of step (b) to produce finely divided metal oxide powder having a mean particle size below one micron; (d) heating said metal oxide powder in an atmosphere of methane and hydrogen to convert said metal oxide powder to metal carbide powder; (e) compressing and sintering said metal carbide powder into a shaped article.
Claim 2
Dependent Claim
102 words
A process for producing sintered metal carbide articles which comprises the steps of: (a) impregnating a carbohydrate material with a compound of a metal; (b) igniting the impregnated material product of step (a) to produce fragile agglomerates of sub-micron size metal oxide particles; (c) comminuting the metal oxide product of step (b) to produce finely divided metal oxide powder having a mean particle size below one micron; (d) heating said metal oxide powder in an atmosphere of methane and hydrogen to convert said metal oxide powder to metal carbide powder; (e) compressing and sintering said metal carbide powder into a shaped article.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein said metal is tungsten, titanium, tantalum, molybdenum, zirconium, hafnium, thorium or mixtures thereof.
Claim 4
Dependent Claim
11 words
The process of claim 2 wherein said carbohydrate material is cellulosic.
Claim 5
Dependent Claim
11 words
The process of claim 3 wherein the cellulosic material is rayon.
Claim 6
Dependent Claim
12 words
The process of claim 2 wherein said carbohydrate material is soluble carbohydrate.
Claim 7
Dependent Claim
12 words
The process of claim 5 wherein said soluble carbohydrate is a sugar.
Claim 8
Dependent Claim
12 words
The process of claim 5 wherein said soluble carbohydrate is a starch.
Claim 9
Dependent Claim
15 words
The process of claim 2 wherein said metal is a mixture of tungsten and coblat.
Claim 10
Dependent Claim
15 words
The process of claim 2 wherein said metal is a mixture of tungsten and nickel.
Claim 11
Dependent Claim
21 words
The process of claim 2 wherein said heating is conducted at a temperature of from about 800° to about 1200° C.
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) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |