A kind of porous spherical rhenium-tungsten alloy powder and its preparation method

Abstract

The invention relates to a porous spherical tungsten rhenium alloy powder and a preparation method thereof, and belongs to the technical field of alloy powder. The mixture of tungsten and rhenium is in the atomic level, the content of the tungsten in proportion by weight ranges from 25% to 90%, and the content of the rhenium in proportion by weight ranges from 10% to 75%. The method includes adopting ammonium perrhenate and ammonium metatungstate as raw materials, configuring into solution, and preparing precursor powder by the spray drying method; depositing and reducing in the atmosphere of hydrogen gas in two steps, namely in the first step,allowing the temperature to be 450 to 550 DEG C and insulating heat for 1 to 2 hours, in the second step, allowing the reducing temperature to be 850 to 950 DEG C, and insulating heat for 2 to 3 hours; and obtaining the porous spherical tungsten rhenium alloy powder. According to the method, process is simple, repeatability and operability are high, the introduction of impurity elements in the preparation process is avoided, the purity of prepared samples is high, and appearance control of a porous spherical tungsten rhenium alloy ball can be implemented by controlling the content of the tungsten, the reducing temperature and heat insulating time.

Description

technical field [0001] The invention belongs to the technical field of alloy powders, in particular to a porous spherical rhenium-tungsten alloy powder and a preparation method thereof. Background technique [0002] Rhenium-tungsten alloy has excellent properties such as high melting point, high hardness, good toughness, wear resistance and corrosion resistance, and is widely used in the fields of national defense industry, aerospace, atomic energy, machinery manufacturing, heating equipment, etc. One of the most critical materials. In recent years, with the rapid development of aviation and aerospace industries, the demand and technical requirements for superalloys are increasing day by day. Rhenium-tungsten alloy is the key material of a new generation of superalloys, especially the advantages of wear resistance and corrosion resistance of rhenium-tungsten alloy. It occupies an important place in the field of surface heat treatment. [0003] In the field of hot cathodes,...

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Problems solved by technology

Pure tungsten powder is an important material for preparing thermionic emission cathodes. The overall performance of cathodes prepared by traditional pure tungsten powders is difficult to meet the requirements of modern electric vacuum devices for electron sources, such as large emission current density, anti-ion bombardment performance, and anti-gas poisoning. performance etc.

Binary or multi-element refractory metal mixed-based cathode materials have low work function, high emission current density and good ion resistance, but many mixed-based powders use liquid-solid doping or solid-solid doping The preparation method of these two methods is easy to introduce impurities, uneven mixing and difficult to prepare powder with good shape, thus affecting the final emission performance of the hot cathode

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