Method of preparing chromium-containing ultrafine WC powder through solid-liquid doping method

Abstract

The invention discloses a method of preparing a chromium-containing ultrafine WC powder through a solid-liquid doping method. The method successively includes the steps of: preparing an ammonium dichromate solution; adding a certain amount of the ammonium dichromate solution to tungsten oxide powder, mixing the components to achieve solid-liquid mixing doping; performing hydrogen reduction, carbon blending, carbonization, cooling, ball milling and sieving to obtain the chromium-containing ultrafine WC powder. The method solves technical problems of non-uniform distribution, large granularity and unsatisfactory effect of inhibiting increase of granularity of WC grains of distribution of Cr3C2 in ultrafine WC powder and hard alloy. When the mixed powder is used for preparing the ultrafine hard alloy, the Cr3C2 has more significant effect of inhibiting the increase of granularity of carbonization grains than a conventional method.

Description

technical field [0001] The invention relates to a method for preparing superfine Cr-containing WC powder by a solid-liquid doping method, and belongs to the field of preparation of superfine tungsten carbide powder and the research field of superfine tungsten carbide-based hard alloy. Background technique [0002] Ultra-fine cemented carbide has the advantages of high hardness, high strength, and good toughness. It is called "double-high" cemented carbide and is widely used in high-efficiency precision tools, micro-drilling, micro-milling, blades, precision molds, etc. The key technical difficulty in preparing ultra-fine cemented carbide lies in how to effectively suppress the growth and coarseness of WC grains during sintering, and the method generally adopted in the industry is to suppress the growth of WC grains by adding grain growth inhibitors. coarse, and the most effective inhibitor is Cr 3 C 2 , Cr 3 C 2 During the sintering process, the solubility of WC grains i...

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Problems solved by technology

[0006] In order to solve Cr 3 C 2 In the ultra-fine WC powder and cemented carbide, the distribution is uneven, the particle size is coarse, and the effect of suppressing the growth and coarsening of tungsten carbide grains is not ideal. The present invention proposes to add a certain amount of ammonium dichromate solution to tungsten oxide, Solid-liquid doping and mixing, and then after hydrogen reduction, carbonization, and carbonization, Cr 3 C 2 WC-Cr with extremely fine particle size and uniform distribution in ultra-fine tungsten carbide 3 C 2 mixed powder

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