Preparation method for porous tungsten bulk material with uniform and controllable pores

A technology of bulk material and porous tungsten, which is applied in the field of powder metallurgy, can solve the problems of difficulty in controlling the uniformity and size of porous tungsten pores, the emission stability of barium tungsten cathode materials, the discount of practical life, and irregular shapes, etc., to achieve Improve emission stability and service life, improve impregnation performance, and shorten cycle time

Active Publication Date: 2016-07-06
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method still uses conventional tungsten powder, which has irregular shape and poor fluidity, which makes it difficult to effectively control the pore uniformity and pore size of porous tungsten, so the emission stability and practical life of barium tungsten cathode materials are greatly reduced.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] The porous tungsten bulk material of this embodiment is prepared according to the following steps:

[0035] Step 1, plasma spheroidization treatment

[0036] Send 100g of tungsten powder into the plasma spheroidization system under the action of carrier gas flow argon for spheroidization treatment, wherein the feeding rate is 2.4g / min, the flow rate of carrier gas is 50L / min, and the powder feeding time is 15 minutes , the prepared spherical tungsten powder is 40.5g, and the powder spheroidization rate is 98%.

[0037] Step 2. Electric vibrating screen treatment

[0038] Put the spherical tungsten powder obtained in step 1 into the metal screen of an electric sieving machine, the mesh number of which is 1250 mesh, vibrate for 5 hours, filter out the unspheroidized tungsten powder, and obtain spherical particles with a particle size of less than 10 μm and uniform distribution. Tungsten powder.

[0039] Step 3. Spark plasma sintering

[0040] Weigh 30g of the spherica...

Embodiment 2

[0042] The porous tungsten bulk material of this embodiment is prepared according to the following steps:

[0043] Step 1, plasma spheroidization treatment

[0044] Send 100g tungsten powder into the plasma spheroidization system under the action of carrier gas flow argon for spheroidization treatment, wherein the feeding rate is 1.0g / min, the flow rate of carrier gas is 70L / min, and the powder feeding time is 28 minutes , the prepared spherical tungsten powder is 35.6g, and the powder spheroidization rate is 98%.

[0045] Step 2. Electric vibrating screen treatment

[0046]Put the spherical tungsten powder obtained in step 1 into the metal screen of an electric sieving machine, the mesh number of which is 1250 mesh, vibrate for 5 hours, filter out the unspheroidized tungsten powder, and obtain spherical particles with a particle size of less than 10 μm and uniform distribution. Tungsten powder;

[0047] Step 3. Spark plasma sintering

[0048] Weigh 30g of the spherical tu...

Embodiment 3

[0050] The porous tungsten bulk material of this embodiment is prepared according to the following steps:

[0051] Step 1, plasma spheroidization treatment

[0052] Feed 100g of tungsten powder into the plasma spheroidization system under the action of carrier gas flow argon for spheroidization treatment, wherein the feeding rate is 4.8g / min, the flow rate of carrier gas is 50L / min, and the powder feeding time is 15 minutes , the prepared spherical tungsten powder is 44.8g, and the powder spheroidization rate is 98%.

[0053] Step 2. Electric vibrating screen treatment

[0054] Put the spherical tungsten powder obtained in step 1 into the metal screen of an electric sieving machine, the mesh number of which is 1250 mesh, vibrate for 5 hours, filter out the unspheroidized tungsten powder, and obtain spherical particles with a particle size of less than 10 μm and uniform distribution. Tungsten powder.

[0055] Step 3. Spark plasma sintering

[0056] Weigh 30g of the spherica...

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Abstract

The invention discloses a preparation method for a porous tungsten bulk material with uniform and controllable pores. The preparation method is characterized by comprising the following steps of: by taking tungsten powder as a raw material, obtaining spherical tungsten powder through plasma balling treatment and electric vibrating and screening treatment; and then, obtaining the porous tungsten bulk material by discharge plasma sintering. According to the preparation method, the porous tungsten bulk material with uniform and controllable pores is obtained by combining a plasma balling technology, an electric vibrating and screening technology and a discharge plasma sintering technology; the preparation method is simple and liable to realize; the control on pores of the product can be realized by regulating the process parameters, so that the porous tungsten bulk material with porosity of 17%-22.5% and pore size of 2-5 mum; the prepared porous tungsten bulk material can be used for remarkably improving the infiltration performance of the material, so that the launch stability of a barium-tungsten cathode is greatly improved, and the service life of the barium-tungsten cathode is prolonged.

Description

technical field [0001] The invention belongs to powder metallurgy technology, in particular to a preparation method of a porous tungsten block material with uniform and controllable pores. Background technique [0002] Various electronic components made of porous tungsten bulk materials have been widely used in aerospace, power electronics and metallurgical industries for a long time, such as barium tungsten cathodes for high current density, emitters of ion engines, and beam targets material etc. In various application fields of porous tungsten materials, its porosity and pore size play a vital role in the performance of the material itself and the performance of components made with it as a carrier. Therefore, a porous tungsten material with controllable porosity, uniform pore size and distribution, and high strength is the key to preparing electron-emitting components with high emission current density, high stability, and long service life. [0003] In Li Yutao's maste...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C1/08C22C1/04C22C27/04B22F3/11
CPCB22F3/11C22C1/045C22C1/08C22C27/04
Inventor 张久兴邱振涛胡可韩翠柳杨新宇李志
Owner HEFEI UNIV OF TECH
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