Method for preparing vanadium carbide powder

A vanadium carbide and powder technology, applied in the field of powder metallurgy, can solve the problems of slow atomic migration, high free carbon content in powder, low surface activation energy, etc., and achieve the effect of reducing free carbon content, reducing carbonization temperature, and expanding applications

Inactive Publication Date: 2005-04-20
CENT SOUTH UNIV
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Problems solved by technology

The particle size of vanadium carbide powder prepared by the two methods is generally in the range of 2.0-3.8 microns, and the free carbon content in the powder is high
In industrial applications, vanadium carbide powder with fine particle size and single phase composition is needed. For example, when preparing ultra-fine cemented carbide, the particle size of WC powder is about 0.2-0.4 microns. If vanadium carbide powder with a particle size of 2-4 microns is used as Grain inhibitor, because the coarse VC powder has a small surface area, low surface activation energy, and slow atomic migration speed, it is difficult to fully exert the effect of inhibiting the grain growth of WC, and the performance of ultra-fine cemented carbide is difficult. progress-improvement

Method used

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Examples

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Effect test

example 1

[0008] First add 3.64 g of V to a solution of 12.4 g of organic acid dissolved in 100 ml of distilled water 2 o 5 , stirring while heating, a clear and transparent blue solution is obtained at 60-80°C, the solution concentration is 13-15%; then the solution is spray-dried in a centrifugal spray dryer, the air inlet temperature: 250°C-350°C , Air outlet temperature: 150°C, rotating speed 30000rpm, flow rate 30ml / min, to obtain amorphous powder containing vanadium complexes and free organic acids, the shape is porous and loose spherical; finally, the powder is heated in a protective atmosphere of 500-600°C with argon Roasting in air, decomposition of vanadium complexes and free organic acids, to obtain V 2 o 3 A powder that is uniformly mixed with free C atoms; then at 850-1000°C, H 2 or H 2 / CH 4 Reduction / carbonization in the atmosphere for 40 to 90 minutes results in superfine VC powder with a narrow particle size distribution and an average particle size of 0.1 micron. ...

example 2

[0010] First add 4.2 g of V to a solution of 10.5 g of organic matter dissolved in 100 ml of deionized water 2 o 5 , stirring while heating, a clear and transparent blue solution is obtained at 60-80°C, the solution concentration is 13-15%; then the solution is spray-dried in a centrifugal spray dryer, the air inlet temperature: 250°C-350°C , Outlet temperature: 150°C, rotating speed 30000rpm, flow rate 30ml / min, to obtain an amorphous powder containing vanadium complex and free organic matter, and the shape of the powder is porous and loose spherical. The powder is calcined at 500°C to 600°C in vacuum, and the vanadium complex and free organic matter are decomposed to obtain V 2 o 3 Mix the powder evenly with the free C atomic level, and finally reduce / carbonize it in vacuum at 850°C-1000°C for 40-90 minutes to obtain ultra-fine VC powder with narrow particle size distribution and an average particle size of 0.1 micron.

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Abstract

A method for preparing powdered vanadium carbide contains following steps: V#-[2]O#-[5] is dissolved in organic acid solution heated and stirred to obtain clarified and transparent solution of 10-40 % concentration at 60-80 degree centigrade, calcinated under protective atmosphere at 850-1000 degree centigrade and carbonized for 40-90 minute to obtain ultrafine powdered vanadium carbide having 0.1 micrometer average size and 20-60 nanometer grain size. The total carbon content of prepared powdered vanadium carbide is 17.75 % , free carbon is reduced to 0.61 % to satisfy the demand in carbide alloy and special steel production. Said invention also extends the use range of VC and provides ultrafine powdered vanadium carbide for other material production industry.

Description

Technical field: [0001] The invention belongs to the manufacture of metal powder in the field of powder metallurgy, in particular to the preparation method of vanadium carbide powder. Background technique: [0002] Vanadium carbide has been widely used in industry as an inhibitor of ultra-fine cemented carbide grains, steel additives, high-temperature coatings, and as a carbon source for synthetic diamonds. There are two types of methods currently used to prepare vanadium carbide: one is to use V 2 o 5 High temperature reduction carbonization method mixed with carbon black, the second is gas phase reduction / vanadium carbide oxide method. The particle size of the vanadium carbide powder prepared by the two methods is generally in the range of 2.0-3.8 microns, and the free carbon content in the powder is high. In industrial applications, vanadium carbide powder with fine particle size and single phase composition is needed. For example, when preparing ultra-fine cemented ca...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/30
Inventor 吴恩熙颜练武钱崇梁
Owner CENT SOUTH UNIV
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