Production method of macrocrystalline WC powder

Abstract

The invention relates to a production method of macrocrystalline WC powder, which comprises the following steps: preparing seed crystal WC powder; then adopting Wo3 or Wo2.9 and C powder as raw materials, and processing by ball mill and mixing with Fe powder, oxides of Fe, Al-Ni alloy powder and the prepared seed crystal WC powder in a proportion; loading an obtained mixture into a boat for melting and carbonizing; and processing obtained alloy by ball milling, pulverizing, iron removing, acid washing for removing impurities, water washing, drying and sieving to obtain the macrocrystalline WC powder. Based on a background technology, the prepared seed crystal WC powder is added, and through a process of dissolving and separating, the method effectively changes the principle of generating WC mainly by C diffusion of the prior conventional process; thus the method breaks through a technical bottleneck of the conventional process, and the seed crystal granularity of the obtained WC powder is increased by more than one time compared with that of the background technology. The invention has the characteristics that the process is advanced and reliable; the produced WC powder has large seed crystal granularity and can be matched with cast WC, and the crystal granularity of a hard alloy product produced by using the macrocrystalline WC powder can be increased by 60-100 percent compared with the background technology; the physical and mechanical properties of the macrocrystalline WC powder are also obviously improved, and the like.

Description

technical field [0001] The invention belongs to a production method of cemented carbide raw material WC powder, in particular to a production method of macrocrystalline WC powder with high purity and excellent performance. The raw material powder can be widely used in the production of mining tools, stamping dies, oil drilling tools and hard surface materials. Background technique [0002] At present, the development and research of WC powder in various countries in the world is in a polarized trend. One is to develop in the direction of ultra-fine WC powder or even nano-scale WC powder; the other is to develop in the direction of high-quality coarse-grain or even large-grain WC powder. The research results prove that coarse-grained WC powder has some unique properties and special uses different from medium and fine-grained WC powder, especially under high temperature conditions, it has a series of advantages such as less structural defects, high microhardness, and small mic...

AI Technical Summary

Problems solved by technology

Although the method has the particle size of WC powder up to millimeter (mm) level, the grain size of cemented carbide products such as drilling tools and stamping dies used for production can reach about 4.0 μm, which can be mixed with cast WC and used in crushers. , cone drills and combined machine tools, related workpieces of machining centers, surface reinforcement of tools, and can be directly used for raw cemented carbide products, and has the advantages of less internal defects, high purity, and excellent performance; but due to the The initial temperature of the reaction between C and tungsten oxide is not high, and it is far from reaching WO 3 or WO 2.9 At the melting point temperature, that is, the carbon reduction reaction starts at a lower temperature, resulting in WO 3 or WO 2.9 Premature loss of oxygen, combined with WO 3 or WO 2.9 The particle size is relatively small, and the crystallization centers are dispersed (many) during carbon reduction, which affects the further growth of WC grains (seed crystals) during carbon reduction, and the obtained WC particle size is also small

Thereby, the grain size (seed crystal) of the obtained coarse-grained WC powder in this method is still relatively small, and it is difficult to further meet the defects of producing high-purity macro-crystalline WC powder with larger grain size and better performance.

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