US4460697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing non-oxide powders
Assignee: Proterial Ltd
•
Filing: 1982-05-21
•
Granted: 1984-07-17
•
Expires: 2002-05-21
Abstract
Abstract Non-oxide powders such as carbides, nitrides, carbides/nitrides and borides are obtained by reducing an oxide powder in a reducing atmosphere, and after or concurrently with the reduction, treating the reduced powder in a carbonizing atmosphere, a nitrogenizing atmosphere, a carbonizing and nitrogenizing atmosphere, or a boronizing atmosphere. As the above oxide powder, there is used a brittle material obtained by rapid cooling of a melted oxide. The non-oxide powders obtained are utilized as a hard component of cemented carbides and cermet. These powders are fine particles having a particle size of 1.0 mu m or smaller and a high purity.
Inventors
- 👤 Hisao Hara
- 👤 Hirohide Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:10
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/5607; C04B35/5626; C01; C01B; C01B21/00; C01B21/06; C01B21/076; C01B21/0765; C01B21/082; C01B21/0828; C01B32/00; C01B32/90; C01B32/907; C01B32/914; C01B32/949; C01B35/00; C01B35/02; C01B35/04; C04B35/58; C04B35/58007; C04B35/58014; C04B35/58021; C04B35/5805; C04B35/58064; C04B35/58071; C01P; C01P2002/00; C01P2002/70; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/62; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
73 words
A process for producing non-oxide powders, which comprises rapidly cooling a molten oxide to produce a brittle oxide material, reducing the oxide material in a reducing atmosphere, and after or concurrently with the reduction, subjecting the resulting reduced powder to heat treatment in a carbon-containing atmosphere, a nitrogen-containing atmosphere, a carbon and nitrogen-containing atmosphere, or a boron-containing atmosphere to obtain non-oxide powder of a carbide, a nitride, a carbide/nitride or a boride, respectively.
Claim 2
Dependent Claim
73 words
A process for producing non-oxide powders, which comprises rapidly cooling a molten oxide to produce a brittle oxide material, reducing the oxide material in a reducing atmosphere, and after or concurrently with the reduction, subjecting the resulting reduced powder to heat treatment in a carbon-containing atmosphere, a nitrogen-containing atmosphere, a carbon and nitrogen-containing atmosphere, or a boron-containing atmosphere to obtain non-oxide powder of a carbide, a nitride, a carbide/nitride or a boride, respectively.
Claim 3
Dependent Claim
12 words
The process according to claim 1 wherein the oxide is metal oxide.
Claim 4
Dependent Claim
35 words
The process according to claim 2, wherein the metal oxide comprises WO 3 or WO 3 admixed with at least one oxide of a metal selected from the group consisting of V, Cr and Mo.
Claim 5
Dependent Claim
30 words
The process according to any one of claims 1 to 3 wherein the atmosphere is put into a plasma condition during the heat treatment by externally adding an electric energy.
Claim 6
Dependent Claim
53 words
The process according to claim 1 wherein a WC powder is obtained by using a WO 3 powder as the oxide, by using a reducing and carbon-containing atmosphere comprising H 2 and CH 4 at a ratio of 1/10 to 100/1, and by heating the WO 3 powder at 800° C. or higher.
Claim 7
Dependent Claim
79 words
The process according to claim 1 wherein a WC powder is obtained by using as the oxide a brittle material obtained by gushing melted WO 3 onto a cooling body and rapidly cooling the WO 3 at a cooling rate of 10 4 ° C./sec or faster, by using a reducing and carbon-containing atmosphere comprising H 2 and CH 4 at a ratio of 1/10 to 100/1, and by heating the WO 3 powder at 800° C. or higher.
Claim 8
Dependent Claim
40 words
The process according to claim 1 wherein the heat treatment is carried out in an atmosphere having a reduced pressure of 0.1 to 20 Torr which is put in a plasma condition with the external addition of an electric energy.
Claim 9
Dependent Claim
78 words
The process according to claim 1 wherein a WC powder is obtained by using as the oxide a brittle material obtained by gushing melted WO 3 onto a cooling body and rapidly cooling the WO 3 at a cooling rate of 10 4 ° C./sec or faster, and by heating a mixture of the brittle material and carbon powder at a temperature of 1400° to 1700° C. firstly in N 2 atmosphere and then in H 2 atmosphere.
Claim 10
Dependent Claim
73 words
The process according to claim 1 wherein a WC powder is obtained by using as the oxide a brittle material obtained by gushing melted WO 3 onto a cooling body and rapidly cooling the WO 3 at a cooling rate of 10 4 ° C./sec or faster, and by reducing this material at 800° C. or higher in H 2 atmosphere and then carbonizing at the same temperature level in CH 4 atmosphere.
Claim 11
Dependent Claim
100 words
The process according to claim 1 wherein a powder of a solid solution comprising tungsten carbide and chromium carbide is obtained by using as the oxide a brittle material obtained by gushing a melted oxide comprising WO 3 and Cr 2 O 3 , a chromium compound or metallic chromium onto a cooling body and rapidly cooling the oxide at a cooling rate of 10 4 ° C./sec or faster, and by heating the brittle material at 1100° C. or higher in a reducing and carbon-containing atmosphere containing H 2 and CH 4 at a ratio of 1/10 to 100/1.
Claim 12
Dependent Claim
98 words
The process according to claim 1 wherein a solid solution powder comprising tungsten carbide and vanadium carbide is obtained by using as the oxide a brittle material obtained by gushing a melted oxide comprising WO 3 and V 2 O 5 , a vanadium compound or metallic vanadium onto a cooling body and rapidly cooling the oxide at a cooling rate of 10 4 ° C./sec or faster, and by heating the brittle material at 1100° C. or higher in a reducing and carbon-containing atmosphere containing H 2 and CH 4 at a ratio of 1/10 to 100/1.
Claim 13
Dependent Claim
96 words
The process according to claim 1 wherein a solid solution powder comprising tungsten carbide and molybdenum carbide is obtained by using as the oxide a brittle material obtained by gushing a melted oxide comprising WO 3 and MoO 3 , a molybdenum compound or metallic molybdenum onto a cooling body and rapidly cooling the oxide at a cooling rate of 10 4 ° C./sec or faster, and by heating the brittle material at 1400° C. or higher in a reducing and carbon-containing atmosphere containing H 2 and CH 4 at a ratio of 1/10 to 100/1.
Claim 14
Dependent Claim
41 words
The process according to claim 10, 11 or 12 wherein the heating is conducted in an atmosphere having a reduced pressure of 0.1 to 12 Torr which is put in a plasma condition with the external addition of an electric energy.
Claim 15
Dependent Claim
20 words
The process according to claim 1, wherein said non-oxide powder has a particle size of not more than 1.0 μm.
Claim 16
Dependent Claim
42 words
The process according to claim 1, further comprising melting an oxide powder to form said molten oxide, forming a thin layer of the brittle oxide material during rapid cooling of said molten oxide, and subjecting said thin layer to said reducing atmosphere.
References Cited (Backward Citations)
US3716627A
Cited
US3932594A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |