A kind of preparation method of zirconium boride dispersion strengthened tungsten powder

Abstract

The invention discloses a preparing method for zirconium boride dispersion strengthening tungsten powder, and relates to metal tungsten powder preparing. In the preparing method, deionized water, ammonium metatungstate and nano zirconium boride particles are prepared into a solution according to the needed proportion, after being subjected to uniform stirring and ultrasonic scattering, the solution is injected into liquid nitrogen, a frozen precursor is obtained, the frozen and dried precursor is roasted in the argon atmosphere with the temperature ranging from 400 DEG C to 600 DEG C, reduction of (500 DEG C-650 DEG C)*2h+ (700 DEG C-900 DEG C)*1 h is conducted in the hydrogen atmosphere, the temperature rise rate is (2-10) DEG C / min, the hydrogen flow is (0.1-1.0) L / min, and the dispersion strengthening tungsten powder is obtained. A tungsten base body obtained through the tungsten powder is sintered, particles are evenly dispersed in the interiors of crystal grains and grain boundaries, the size of the particles is the nano level, an obtained block is subjected to the mechanical test, and it is proved that the mechanical performance of the block is obviously improved. The dispersion strengthening tungsten prepared through the method has very high grain-boundary strength; and meanwhile, compared with traditional metal carbide and rare earth oxide dispersion particles, zirconium boride dispersion strengthening can reach a higher strengthening and toughening effect under the smaller adding amount.

Description

technical field [0001] The invention belongs to the preparation of metal materials, in particular to the preparation of metal tungsten powder. Background technique [0002] Tungsten is a metal material widely used in various industrial fields. It has the characteristics of high density, high melting point, high thermal conductivity, and low thermal expansion coefficient. It has unique applications in military industry, nuclear industry, and aerospace. Under these application conditions, tungsten needs to be frequently subjected to coupled external fields, such as high temperature, radiation and thermal shock, etc. Under these working conditions, tungsten materials are prone to failure, mainly manifested as brittle fracture under external force and regeneration under thermal effect. Crystal embrittlement. For tungsten whose crystal structure is body-centered cubic, its grain boundary strength is poor, and it is a place where fractures easily occur. Under the action of exter...

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Problems solved by technology

For mechanical alloying, it needs to consume a lot of energy. During the mixing process, impurities are easily introduced due to the violent movement of the tank body and the grinding ball. Moreover, the preparation of dispersed tungsten powder by this method has a long cycle and poor economy.

The precipitation coating method can obtain doped tungsten powder with good dispersion and uniform quality, but because this method requires a large amount of acid and alkali to prepare and control the pH value of the solution for precipitation coating reaction, it is an environmentally unfriendly method

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