US4670408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of carbide-boride products
Assignee: Max-Planck-Gesellschaft zur Förderung der Wissenschaften eV
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Filing: 1985-09-18
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Granted: 1987-06-02
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Expires: 2005-09-18
Abstract
Abstract A process for the preparation of boron carbide/transition metal boride mod articles comprising hot pressing a mixture of from 25 to 75% by weight of boron carbide, from 15 to 40% by weight of boron, from 0 to 8% by weight of silicon, from 10 to 50% by weight of tungsten and/or titanium carbide, and from 0 to 6% by weight of cobalt.
Inventors
- 👤 Gunter Petzow
- 👤 Heinrich Hofmann
- 👤 Kurt Weiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:52
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/5805; C04B35/56; C04B35/563; C04B35/622; C04B35/64; C04B35/645; C22; C22C; C22C29/00; C22C29/14
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A process for the preparation of molded articles based on boron carbide/transition metal boride selected from the group consisting of tungsten boride, titanium boride, or mixtures thereof comprising intimately mixing in finely particulate form, the following composition: 25-75 weight percent boron carbide 14-40, weight percent boron 10-50 weight percent tungsten and/or titanium carbide 0-6 weight percent cobalt, and 0-8 weight percent silicon, and hot pressing the powder obtained at temperatures between 1550° C. and 1850° C. to convert the carbide into the corresponding boride to produce molded articles.
Claim 2
Dependent Claim
88 words
A process for the preparation of molded articles based on boron carbide/transition metal boride selected from the group consisting of tungsten boride, titanium boride, or mixtures thereof comprising intimately mixing in finely particulate form, the following composition: 25-75 weight percent boron carbide 14-40, weight percent boron 10-50 weight percent tungsten and/or titanium carbide 0-6 weight percent cobalt, and 0-8 weight percent silicon, and hot pressing the powder obtained at temperatures between 1550° C. and 1850° C. to convert the carbide into the corresponding boride to produce molded articles.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the boron is in amorphous form.
Claim 4
Dependent Claim
22 words
A process of claim 1 wherein the transition metal carbide and cobalt are used in the form of hard metal alloy balls.
Claim 5
Dependent Claim
17 words
The process of claim 3 wherein the balls have a diameter of from 0.5 to 2.5 mm.
Claim 6
Dependent Claim
36 words
The process of claim 1 wherein the boron carbide powder is first mixed with boron and silicon and the resulting powder is comminuted together with tungsten carbide and cobalt, or tungsten carbide, titanium carbide, and cobalt.
Claim 7
Dependent Claim
14 words
The process of claim 5 wherein the comminuting is carried out in a solvent.
Claim 8
Dependent Claim
21 words
The process of claim 5 wherein the tungsten or titanium carbide is replaced at least partially by other transition metal carbides.
Claim 9
Dependent Claim
23 words
The process of claim 7 wherein the other carbide is selected from the group consisting of zirconium carbide, chromium carbide, and tantalum carbide.
Claim 10
Dependent Claim
20 words
The process of claim 5 wherein the comminution is carried out to a particle size of less than 1 μm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |