US3661557A
Expired / Lapsed
US
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Process for the production of metal powder
Assignee: REDERIAKTREBOLAGET NORDSTJERNA
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Filing: 1969-08-20
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Granted: 1972-05-09
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Expires: 1989-08-20
Abstract
Abstract The invention relates to a process for affecting grain growth in the production of metal powder from the metals W, Mo, Ta, Nb or Re or from alloys comprising one or several of these metals, by reduction in a gas phase of the metal halides by means of hydrogen gas. The reduction may be carried out in one or several steps so that partially or completely reduced metal powder is obtained. If there is partially reduced metal powder, this powder is exposed to at least one additional treatment consisting of the mechanical decomposition of the powder and/or heat treatment at a temperature of 400*-1,200* C., preferably 700*-1,100* C. in an atmosphere containing some form of halogen. If there is a completely reduced metal powder, this powder is exposed to at least one additional treatment consisting of either a heat treatment at a temperature of 400*-1,200* C., preferably 700*1,100* C. in an atmosphere containing some form of halogen or the mechanical decomposition of the powder followed by said heat treatment.
Inventors
- 👤 Elis Kjell Ake Svanstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:02
CPC Classifications
C; C22; C22B; C22B5/00; C22B5/02; C22B5/16; B; B22; B22F; B22F1/00; B22F1/14; B22F1/142; B22F9/00; B22F9/16; B22F9/18; B22F9/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
In a method for affecting grain growth in the production of metal powder of metals selected from the group consisting of W, Mo, Ta, Nb, Re and alloys thereof by reducing a corresponding metal halide in a gas phase by means of hydrogen gas, the improvement comprising the following steps in the order named: a. reducing the halide to form a partially reduced powder; b. comminuting the powder mechanically; c. treating the powder at a temperature of 400-1,200* C. in an atmosphere comprising a halogen; and d. further reducing the powder to form a completely reduced metal powder.
Claim 2
Dependent Claim
16 words
A method as recited in claim 2, wherein the treating atmosphere consists of hydrogen halide gas.
Claim 3
Dependent Claim
89 words
In a method for affecting grain growth in the production of metal powder of metals selected from the group consisting of W, Mo, Ta, Nb, Re, and alloys thereof by reducing a corresponding metal halide in a gas phase by means of hydrogen gas, the improvement comprising the following steps in the order named: a. reducing the halide to form a completely reduced metal powder; b. comminuting the metal powder mechanically; and c. treating the metal powder at a temperature of 400-1,200* C. in an atmosphere comprising a halogen.
Claim 4
Dependent Claim
90 words
In a method for affecting grain growth in the production of metal powder of metals selected from the group consisting of W, Mo, Ta, Nb, Re and alloys thereof by reducing a corresponding metal halide in a gas phase by means of hydrogen gas, the improvement comprising the following steps in the order named: a. reducing the halide to form a partially reduced powder; b. mixing coarse-grained and fine-grained partially reduced powder: c. comminuting the powder mechanically; and d. further reducing the powder to form a completely reduced metal powder.
Claim 5
Dependent Claim
101 words
In a method for affecting grain growth in the production of metal powder of metals selected from the group consisting of W, Mo, Ta, Nb, Re and alloys thereof by reducing a corresponding metal halide in a gas phase by means of hydrogen gas, the improvement comprising the following steps in the order named: a. reducing the halide to form a partially reduced powder; b. mixing coarse-grained and fine-grained partially reduced powder; c. treating the powder at a temperature of 400-1,200* C. in an atmosphere comprising a halogen; and d. further reducing the powder to form a completely reduced metal powder.
Claim 6
Dependent Claim
106 words
In a method for affecting grain growth in the production of metal powder of metals selected from the group consisting of W, Mo, Ta, Nb, Re and alloys thereof by reducing a corresponding metal halide in a gas phase by means of hydrogen gas, the improvement comprising the following steps in the order named: a. reducing the halide to form a partially reduced powder; b. mixing coarse-grained and fine-grained partially reduced powder; c. comminuting the powder mechanically; d. treating the powder at a temperature of 400-1,200* C. in an atmosphere comprising a halogen; and e. further reducing the powder to form a completely reduced metal powder.
Claim 7
Dependent Claim
89 words
In a method for affecting grain growth in the production of metal powder of metals selected from the group consisting of W, Mo, Ta, Nb, Re and alloys thereof by reducing a corresponding metal halide in a gas phase by means of hydrogen gas, the improvement comprising the following steps in the order named: a. reducing the halide to form a completely reduced metal powder; b. mixing coarse-grained and fine-grained metal powder; and c. treating the powder at a temperature of 400-1,200* C. in an atmosphere comprising a halogen.
Claim 8
Dependent Claim
95 words
In a method for affecting grain growth in the production of metal powder of metals selected from the group consisting of W, Mo, Ta, Nb and Re and alloys thereof by reducing a corresponding metal halide in a gas phase by means of hydrogen gas, the improvement comprising the following steps in the order named: a. reducing the halide to form a completely reduced metal powder; b. mixing coarse-grained and fine-grained metal powder; c. comminuting the powder mechanically; and d. treating the powder at a temperature of 400-1,200* C. in an atmosphere comprising a halogen.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |