A kind of preparation method of direct heating type high temperature tungsten-rhenium alloy cathode

Abstract

A method for preparing a direct-heating high-temperature tungsten-rhenium alloy cathode, the method steps comprising: mixing metal tungsten powder and rhenium powder to obtain evenly mixed tungsten-rhenium alloy powder; mixing the tungsten-rhenium alloy powder with 1.5-3 wt% nitric acid Mix the cotton solution evenly, apply the mixed solution on the surface of the tungsten wire cathode substrate, and bake; put the tungsten wire coated with tungsten-rhenium alloy powder on the surface into a high-temperature hydrogen furnace, and keep it warm at 1500±50°C for 5 to 10 minutes. The tungsten-rhenium alloy layer is prepared; then, the tungsten wire with the tungsten-rhenium alloy layer sintered on the surface is placed in an air pressure of 10 ‑3 ~10 ‑1 In the benzene atmosphere of Pa, the high-temperature chemical reaction is carried out at the temperature of the tungsten wire at 2000-2400K, and the reaction time is 0.5-2 minutes, and the direct-heating high-temperature tungsten-rhenium alloy cathode is prepared. The direct-heating high-temperature tungsten-rhenium alloy cathode of the invention can increase the emission current density of the pure tungsten wire cathode for a magnetron, reduce the working temperature and surface evaporation rate of the pure tungsten wire cathode, thereby prolonging the life of the cathode and the magnetron.

Description

technical field [0001] The invention relates to a preparation method of a direct-heating high-temperature tungsten-rhenium alloy cathode. Background technique [0002] At present, magnetrons are developing towards high output power. Ordinary barium tungsten cathodes, oxide cathodes, etc. are not resistant to electron and ion bombardment, are not resistant to anode high voltage, and are prone to ignition. application in magnetrons. Therefore, in medium and high power continuous wave magnetrons with high anode voltage, the directly heated pure tungsten (W) wire cathode with weak emission ability has been widely used. Compared with ordinary oxide cathodes and barium tungsten cathodes, pure W wire cathodes have the advantages of high emission stability, strong resistance to electron and ion bombardment, and strong resistance to poisoning. However, in the case of normal output power, the cathode of medium and high-power continuous wave magnetron generally works at a temperature...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method for preparing a direct-heating high-temperature tungsten-rhenium alloy cathode, which solves the problem that the life of the pure W wire cathode in the medium and high-power continuous wave magnetron leads to the end of the life of the magnetron. Improve the emission current density of the pure W filament cathode, reduce the operating temperature of the cathode, and prolong the service life of the cathode

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