Preparation method for rare earth oxide doped tungsten powder

Abstract

The invention provides a preparation method of rare earth oxide doped tungsten powder, belonging to a technical field of rare earth refractory metal material. The process flow is that: firstly, a precursor powder is obtained by adopting low-temperature combustion synthesis, wherein the precursor powder is a uniform mixture of rare earth oxide (at least one of Sc2O3, Y2O3, La2O3, CeO2, ZrO2, Gd2O3 and Eu2O3) and tungsten oxide; secondly, the precursor powder undergoes calcination in a muffle furnace; lastly, two-step reduction is carried out in the atmosphere of hydrogen or dissociated ammonia. Easy-reduction tungsten oxide is reduced to tungsten matrix powder, and the rare earth oxide that can not be reduced is reserved, thereby the rare earth oxide doped tungsten powder is obtained. The content of the rare earth oxide in the rare earth oxide doped tungsten powder is 0.05-35 wt%. The advantage of the invention is that target element and organic carbon source are capable of forming a highly dispersed system, and particle sizes of the obtained oxide are uniform and fine. The method is suitable for industrialization production because of low cost of raw materials, quick reaction speed, low energy consumption and simple technology.

Description

technical field [0001] The invention belongs to the technical field of rare earth refractory metal materials, and particularly provides a method for preparing rare earth oxide doped tungsten powder by a low-temperature combustion synthesis method. Background technique [0002] Vacuum tube devices are essential equipment for national defense equipment such as radar, communications, electronic countermeasures, telemetry and remote control, and precision guidance, as well as civilian fields such as high-energy particle accelerators, weather radars, microwave communications, and satellite communications. Tungsten has a series of advantages such as high melting point, high specific gravity, high elastic modulus, high temperature strength, low vapor pressure and low expansion coefficient. etched electrode material. The cathode is the electron emission source of the vacuum tube device, and the performance of the cathode material is directly related to the performance and service l...

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Problems solved by technology

At present, there are three main doping methods of rare earth oxides: solid-solid doping is directly introduced into rare earth oxides in the form of mechanical mixing, which has the problems of coarse structure and obvious oxide segregation; liquid-solid doping is mixed with rare earth nitrate solution The introduction of rare earth oxides in the form of solid refractory metal compounds refines the structure and improves the electron emission performance, but the uniformity of rare earth oxides is still limited; liquid-liquid doping (traditional sol-gel method) adds Rare earth nitrate solution and ammonium metatungstate solution to obtain oxide doped refractory metal, grain refinement and uniform distribution of rare earth elements improve electron emission performance, but there are problems of long time and low efficiency, tungsten powder and oxidation The particles are easy to grow

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