Preparation method of tungsten powder for cathodes and application thereof

A technology of tungsten powder and cathode, which is applied in the field of tungsten powder preparation, can solve the problems of non-concentrated particle size distribution, easy water absorption and high impurities of tungsten powder, and achieve the effect of simple method and few steps

Active Publication Date: 2014-06-25
HUADONG PHOTOELECTRIC TECHN INST OF ANHUI PROVINCE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for preparing tungsten powder with concentrated particle size distribution and high purity in order to overcome the defects of non-concentrated particle size distribution, high impurities and easy water absorption in the air in the prior art.

Method used

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  • Preparation method of tungsten powder for cathodes and application thereof

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preparation example Construction

[0030] The preparation method of the tungsten powder used for cathode provided by the present invention, wherein, the method comprises the following steps:

[0031] (1) In a hydrogen atmosphere, heat-treat the tungsten powder and then cool it;

[0032] (2) Ball mill the cooled tungsten powder;

[0033] (3) Screen the tungsten powder after ball milling;

[0034] Wherein, the heat treatment is to raise the temperature of the tungsten powder to 1850-2000° C. at a heating rate of 455-495° C. / min, and keep it at this temperature for 100-140 minutes.

[0035] In the present invention, the tungsten powder is heated to 1850-2000°C at a heating rate of 455-495°C / min for heat treatment in a hydrogen atmosphere, and the oxide layer on the surface of the tungsten powder is reduced under the action of hydrogen to obtain high-purity tungsten powder. The cooled tungsten powder is ball milled and screened to obtain a high-purity tungsten powder with a particle size distribution of 3-5 μm an...

Embodiment 1

[0047]Put lint-free paper on each of the left and right trays of the balance, weigh the tungsten powder, put the tungsten powder into the molybdenum bowl with a horn spoon, and level it out. With the capacity of the molybdenum bowl being 100 parts by volume, the amount of tungsten powder is 20 Parts by volume; then put the molybdenum bowl with tungsten powder into a dry bottle, heat treatment in a tungsten mesh hydrogen furnace, the working atmosphere is hydrogen, and heat up to 1900°C at a heating rate of 470°C / min and keep it for 120min, then cool to 20°C.

[0048] Put the tungsten powder obtained after high-temperature treatment and cooling in the tungsten mesh hydrogen furnace into an agate bowl, and use an agate rod to crush it into tungsten powder particles with a particle size of 3mm-5mm1. Then if figure 1 As shown, put 250g tungsten powder particles 1, 5 first agate balls 2 of Ф25mm, 11 second agate balls 3 of Ф15mm and 6 third agate balls 4 of Ф10mm into a 0.4L agate...

Embodiment 2

[0052] Carry out according to the method of Example 1, the difference is that the tungsten powder is heated up to 1940°C at a heating rate of 480°C / min in the presence of hydrogen. The tungsten powder obtained in this embodiment is off-white. The particle size and particle distribution of the tungsten powder obtained in this embodiment and the purity of the tungsten powder are detected. It is known that the particle size of the tungsten powder particle is 3-5 μm. The weighted width of particle size is 57.33%, and the purity of tungsten powder is 99.999%.

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Abstract

The invention discloses a preparation method of tungsten powder for cathodes and application thereof. The preparation method comprises the following steps of (1) heating the tungsten powder to 1850 DEG C-2000 DEG C at the speed of 455 DEG C / min-495 DEG C / min in the hydrogen atmosphere, keeping the temperature for 100min-140min, and cooling the tungsten powder; (2) performing ball-milling on the cooled tungsten powder; (3) screening the tungsten powder subjected to ball-milling. Grain sizes of the tungsten powder prepared by the preparation method range from three mum to five mum, grain size distribution of the tungsten powder is concentrated relatively, the purity of the tungsten powder is 99.995 percent-99.999 percent, and requirements for quality of the tungsten powder required by preparation of the cathodes can be met.

Description

technical field [0001] The invention relates to the field of tungsten powder preparation, in particular to a preparation method and application of tungsten powder used for cathodes. Background technique [0002] The cathode is a key factor affecting the life of a traveling wave tube. When designing the cathode, it is necessary to fully consider many factors such as ion bombardment resistance, high voltage resistance, poisoning resistance, vibration resistance, impact resistance, spark resistance, emission capability, and long life. [0003] The barium tungsten cathode is one of the cathodes, and its bulk structure is composed of an active material capable of producing barium metal and a tungsten sponge as a carrier. Its working mechanism is the monoatomic layer dipole theory, that is, at the working temperature, the reduced barium in the active material diffuses to the surface along the pores in the tungsten sponge to form a monoatomic barium layer, and the barium-based tun...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F9/04
Inventor 吴华夏孟昭红陈爱民于晨晨卞磊邹莺歌王莹
Owner HUADONG PHOTOELECTRIC TECHN INST OF ANHUI PROVINCE
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