Method for preparing pressing type barium-tungsten cathode through microwave sintering

A technology of microwave sintering and barium tungsten cathode, which is applied to other manufacturing equipment/tools, mechanical equipment, engine components, etc., can solve the problems of poor emission performance and grain growth, and achieve improved emission performance, significant growth, and emission current The obvious effect of density

Inactive Publication Date: 2019-05-28
BEIJING UNIV OF TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, due to the high activity of submicron and nanoscale powders, the early compressed barium tungsten cathodes are prone to rapid grain growth during conventional sintering, resulting in extremely poor emission performance, and have not been deeply studied.

Method used

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  • Method for preparing pressing type barium-tungsten cathode through microwave sintering
  • Method for preparing pressing type barium-tungsten cathode through microwave sintering
  • Method for preparing pressing type barium-tungsten cathode through microwave sintering

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Embodiment 1

[0025] The invention provides a method for preparing a pressed barium tungsten cathode by microwave sintering, which comprises the following steps:

[0026] (1) Take 3 100ml beakers that have been cleaned and dried with deionized water, and the analytically pure Ba(NO 3 ) 2 , Ca(NO 3 ) 2 4H 2 O, Al(NO 3 ) 3 9H 2 O, according to c(BaO):c(CaO):c(Al 2 o 3 ) into beakers at a ratio of 4:1:1, pour an appropriate amount of deionized water, and prepare aqueous solutions of barium nitrate, calcium nitrate, and aluminum nitrate respectively, and use a stirrer to fully stir until the three solutions are completely free. The precipitate is transparent.

[0027] (2) Mix the three solutions prepared in step (1), and then stir again until the solution is transparent without precipitation.

[0028] (3) Take a 300ml beaker that has been cleaned and dried with deionized water, put analytically pure ammonium metatungstate into the beaker, pour in an appropriate amount of deionized wat...

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Abstract

The invention provides a method for preparing a pressing type barium-tungsten cathode through microwave sintering, and belongs to the technical field of refractory metal cathode materials. Ammonium metatungstate, barium nitrate, calcium nitrate and aluminium nitrate of an analytical reagent are dissolved in deionized water, and after liquid-liquid doping is completed, submicron-order active salt doped tungsten powder is obtained through the combination of spray drying and a two-stage reduction method. Then, the barium-tungsten cathode with a submicron structure is obtained through pressing andmicrowave sintering processes. The experimental result shows that compared with a method for preparing a cathode through conventional sintering, the sintering temperature of the microwave sintering process is low, the sintering time is short, and the sintering power is greatly reduced. The microstructure of the cathode prepared through microwave sintering is obviously improved, the emitting performance of the cathode is improved to a certain degree, the drawn pulse emission current density can reach 6.52 A/cm<2> at the temperature of 1,050 DEG Cb, and compared with the drawn emission currentdensity, being 3.46 A/cm<2>, of the cathode prepared through conventional sintering at the temperature of 1,050 DEG Cb, the pulse emission current density is obviously increased.

Description

technical field [0001] The invention belongs to the technical field of refractory metal cathode materials, and more specifically relates to a method for preparing pressed barium-tungsten cathodes by microwave sintering. Background technique [0002] Microwave vacuum electronic devices are electronic devices that generate and amplify microwaves by interacting with electron beams and microwave electromagnetic fields. They are widely used in high-frequency oscillation and high-power amplification. It is widely used in daily life and plays an important role. Among them, the cathode is known as the "heart" of high-power, high-frequency microwave vacuum electronic devices, and its performance directly affects the characteristics and service life of the device. [0003] The active salt is mixed with tungsten powder, and after pressing and sintering, the pressed barium tungsten cathode can be obtained directly. Compared with the impregnated barium tungsten cathode, the preparation ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F3/10B22F5/00C22C1/04C22C24/00
Inventor 刘伟李俊辉王金淑周帆杨韵斐潘兆柳吴浩李世磊张小可
Owner BEIJING UNIV OF TECH
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