Extra-coarse hard alloy parcel powder and preparation method thereof

Abstract

The invention discloses extra-coarse hard alloy parcel powder and a preparation method thereof. The preparation method comprises the steps of adding tungsten carbide powder of which the average Fisher particle size is 3-8 microns and other hard phase carbide powder of which the average Fisher particle size is 0.5-1.5 microns into a soluble cobalt salt solution, wherein the tungsten carbide powder and the hard phase carbide powder are used as a nucleating agent; performing chemical coprecipitation wrapping reaction on ammonium oxalate serving as a precipitator to enable the produced cobalt oxalate to be precipitated to the surfaces of the tungsten carbide powder and the hard phase carbide powder, and performing filtration, washing, drying and hydrogen reduction to obtain hard alloy parcel powder. The extra-coarse hard alloy parcel powder comprises the following components in percentage by weight: 6-12 percent of cobalt, 0-2 percent of crystalline grain inhibitor and the balance being tungsten carbide, wherein the average Fisher particle size of the tungsten carbide is 3-8 microns.

Description

technical field [0001] The invention relates to an ultra-coarse cemented carbide coating powder and a preparation method thereof. Background technique [0002] Ultra-coarse cemented carbide has high red hardness, good thermal fatigue resistance and thermal shock resistance, and is widely used in mining, road digging and stamping dies, cold heading dies, rolls and other fields under extreme working conditions. The heavy-duty coal shearer picks and hard rock roadheaders supporting foreign large-scale coal shearers all use cemented carbide with a grain size higher than 4 μm. When the grain size of tungsten carbide reaches more than 5 μm, the cemented carbide can obviously change its plasticity while maintaining good strength, and the product reliability is greatly improved. At present, it is difficult to prepare grain size of more than 5 μm and good microstructure in my country. , Ultra-coarse cemented carbide with high comprehensive performance. [0003] The mixing proces...

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Problems solved by technology

However, the application of the wet grinding process to the preparation of ultra-coarse cemented carbide has obvious disadvantages: during the wet grinding process, the coarse tungsten carbide secondary particles and primary particles are easily broken, so the raw material tungsten carbide powder required for the preparation of ultra-coarse cemented carbide The particle size needs to be more than ten or even tens of microns, and the carbonization temperature in the preparation process of large particle size tungsten carbide powder is high, resulting in great energy consumption; ball milling causes powder particle breakage, crystal form distortion, and powder particle size is difficult to control; at the same time , the ball milling time required for wet milling is long, and the consumption of wet milling media such as alcohol and gasoline is large, which increases the production cost

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