A method for prepare a rhenium-impregnated scandium-tungsten-based alloy cathode

Abstract

A method for prepare a rhenium impregnated scandium-tungsten base alloy cathode comprises mixing metal scandium powder and tungsten pow to obtain uniformly mixed scandium-tungsten alloy powder; The scandium-tungsten alloy powder is uniformly mixed with (1.5-3) wt% nitrocellulose solution, the mixed solution is applied on the surface of the tungsten wire cathode substrate and baked; Putting tungsten wires with scandium-tungsten alloy powder on the surface into a high-temperature hydrogen furnace, keeping the temperature at 1350 +-50 DEG C for 5-10 minutes to prepare a scandium-tungsten base alloy layer; Then, impregnating a mixed solution of metal rhenium powder and (1.5-3) wt% nitrocellulose solution on the surface of the scandium-tungsten based alloy layer, and baking; The tungsten wire impregnated with rhenium powder on the surface of Sc-W based alloy layer was put into a high temperature hydrogen furnace and kept at 1500 +/- 50 DEG C for 5 - 10 minutes. The cathode of Re-impregnatedSc-W based alloy was prepared. The rhenium-impregnated scandium-tungsten-base alloy cathode prepared by the method of the invention can improve the emission current density of the pure tungsten wirecathode for magnetron, reduce the working temperature and the surface evaporation rate of the pure tungsten wire cathode, thereby prolonging the service life of the cathode and the magnetron.

Description

technical field [0001] The invention relates to a preparation method of rhenium-impregnated scandium-tungsten-based 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 above ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a preparation method of rhenium-impregnated scandium-tungsten-based 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 short life of the magnetron, and has the following advantages: 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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