Method for preparing micro spherical tungsten powder

A spherical and tungsten powder technology, applied in the field of powder metallurgy powder production, can solve the problem of high cost of spherical tungsten powder, and achieve the effect of simplifying production technology and reducing production cost

Inactive Publication Date: 2009-05-20
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] To sum up, the existing technologies for preparing spherical tungsten powder all need to use tungsten powder prepared by conventiona...

Method used

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  • Method for preparing micro spherical tungsten powder
  • Method for preparing micro spherical tungsten powder
  • Method for preparing micro spherical tungsten powder

Examples

Experimental program
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Effect test

Embodiment 1

[0016] Under the condition of ultrasonic stirring, add 1ml of dispersant BYK-154 into 100ml of saturated ammonium tungstate solution and mix well. Then continue to add 15 ml of concentrated sulfuric acid under the stirring effect of ultrasonic wave, finally generate precipitation after the reaction. After the precipitate is filtered out, it is dried in a drying oven, and then ground and crushed into powder. Then place it in a hydrogen reduction furnace for reduction at 680°C to obtain spherical tungsten powder with an average particle size of 1.2 microns.

Embodiment 2

[0018] Under the condition of ultrasonic stirring, add 2ml of dispersant BYK-163 into 100ml of saturated ammonium tungstate solution and mix well. Then continue to add concentrated sulfuric acid 18ml under the stirring effect of ultrasonic wave, finally generated precipitation after the reaction. After the precipitate is filtered out, it is dried in a drying oven, and then ground and crushed into powder. Then place it in a hydrogen reduction furnace for reduction at 720°C to obtain spherical tungsten powder with an average particle size of 2.5 microns.

Embodiment 3

[0020] Under the condition of ultrasonic stirring, add 1.0g of dispersant sodium lauryl sulfate into 100ml of saturated ammonium tungstate solution and mix well. Then continue to add 17 ml of concentrated sulfuric acid under the stirring effect of ultrasonic waves, and finally generate a precipitate after the reaction. After the precipitate is filtered out, it is dried in a drying oven, and then ground and crushed into powder. Then place it in a hydrogen reduction furnace for reduction at 700°C to obtain spherical tungsten powder with an average particle size of 2.0 microns.

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Abstract

The invention belongs to the field of powder production in powder metallurgical industry, and relates to a method for preparing microfine spherical tungsten powder. The method is characterized in that concentrated sulphuric acid is comprehensively used as a precipitating agent and a dispersing agent for ammonium tungstate to form a precipitate of tungsten acid; and the precipitate is dried and reduced by hydrogen to form tungsten powder. The method comprises the following technological steps: a saturated solution ammonium tungstate and a dispersing agent are stirred by ultrasonic waves to be mixed uniformly, wherein the dispersing agent is BYK-154, BYK-163, sodium dodecyl sulfate, or dodecyl sodium sulfate, and the amount of the dispersing agent added is 1 to 2 percent of that of the solution of ammonium tungstate; concentrated sulphuric acid is added into the mixture by the stirring of ultrasonic waves, wherein the volume ratio of the concentrated sulphuric acid to the solution of ammonium tungstate is (15-20):100; and the precipitate is formed during stirring, filtered off, dried, crushed and placed into a hydrogen reduction furnace to be reduced to obtain microfine spherical tungsten powder with a granularity of between 1.2 and 2.8 micrometers, wherein the reduction temperature is between 680 and 720 DEG C. The method simplifies the production technology for producing tungsten powder and can reduce production cost of spherical tungsten powder obviously.

Description

technical field [0001] The invention belongs to the field of powder-making by powder metallurgy, and relates to a preparation method of fine spherical tungsten powder. Background technique [0002] Tungsten powder commonly used in industry is obtained by reducing tungsten oxide with hydrogen. The shape of tungsten powder particles prepared by the reduction method is irregular, the fluidity of this tungsten powder is poor, and the bulk density is low. In recent years, the demand for spherical tungsten powder has been increasing day by day, and it is widely used in powder metallurgy processes such as the preparation of porous materials, thermal spraying and injection molding. Porous tungsten prepared with spherical tungsten powder has more uniform pores, so it is gradually replacing conventional tungsten powder and used to make porous tungsten parts, such as cathodes of high-power pulsed microwave tubes, barium-tungsten cathodes of electronic tubes, sweating materials for roc...

Claims

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Application Information

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IPC IPC(8): B22F9/26
Inventor 林涛李振邵慧萍杨国庆罗骥郭志猛郝俊杰
Owner UNIV OF SCI & TECH BEIJING
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