Preparation method of vanadium carbide

Release time:

2022-10-13 09:31

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Vanadium carbide not only has the general characteristics of transition metal carbides such as high hardness, melting point and high temperature strength, according to literature reports, the thermodynamic stability of various carbide inhibitors determines the restraint effect, but also has good electrical and thermal conductivity, so it is widely used in iron and steel metallurgy, hard alloy, electronic products, catalysts and high temperature coating materials and other fields, then, let's learn about the preparation method of vanadium carbide together!

With the use of cemented carbide in high-tech weapons and equipment, science and technology and nuclear energy more and more widely, for nano-sized cemented carbide powder, 1,1~150 sintering grain growth has occurred, corrosion inhibitor dissolution temperature is high, not only difficult to get restraint, and sometimes make the performance of cemented carbide deterioration. Therefore, it is necessary to further optimize the properties of WC alloys by refining their grains and preparing cemented carbides with ultrafine or even nanostructures. As the affinity of carbon to oxygen increases with the increase of temperature and the affinity of various metals to oxygen decreases with the increase of temperature, the preparation of nano vanadium carbide powder has also attracted the attention of many researchers. Carbothermal reduction is a common traditional method for the preparation of metal carbides. Contamination of the product with other impurities can be eliminated. Therefore, the carbon thermal reduction method has the characteristics of simple process, easy access to raw materials, good repeatability, and the corresponding metal or carbide can be prepared by carbon reduction oxide at high temperature. The main products of carbon reduction are CO and CO2, which have high practical value.

Because vanadium carbide has the general characteristics of transition metal carbide such as high hardness, melting point and high temperature strength, the addition of vanadium carbide to steel can improve the comprehensive properties of steel such as wear resistance, corrosion resistance, toughness, strength, ductility, hardness and thermal fatigue resistance, and at the same time has good electrical conductivity and thermal conductivity, so it is widely used in iron and steel metallurgy, cemented carbide, electronic products, catalysts and high temperature coating materials. Vanadium carbide has also been widely used as a new type of catalyst. In addition, vanadium carbide can also be used as a new carbon source for the synthesis of diamond. The important role of vanadium carbide is used as a grain restraint agent in the field of cemented carbide and metal ceramics, and can be used as a wear-resistant material for different cutting and wear-resistant tools. In addition, due to its high activity, selectivity, stability, and ability to resist "catalyst poisoning" in hydrocarbon reactions, the growth of WC grains during the sintering process is effectively prevented.

manufacturing methods of vanadium carbide:

1. carbothermal reduction method

Carbothermal reduction method is a method for preparing vanadium carbide powder by solid carbon reduction of vanadium oxide, which is a common and traditional method for preparing vanadium carbide powder. However, the carbonization is generally completed at a higher temperature (1500(1) 600), with the increase of temperature, the grain size of the powder is generally more than 4 m, the method is simple, good repeatability, and has high practical value.

2. gas phase reduction method

The gas phase reduction method is a method to obtain vanadium carbide powder with a particle size of 17nm (specific surface area of 60 m 2/g) by providing a carbon source through the cracking of gaseous hydrocarbon molecules, and to obtain ultrafine or nano vanadium carbide. V2O5 is reduced by CH4/H2 mixed gas.

3. Precursor method

The precursor method is to fully mix the vanadium source and the carbon source by mixing the solution, and then further heat-treat the solid phase precursor to obtain the nano-vanadium carbide powder, and heat-evaporate or spray-dry the solution to obtain the solid phase precursor containing the vanadium source and the carbon source.

4. in situ synthesis-mechanical alloying method

In-situ synthesis is a new method for the preparation of composite materials developed in recent years. The self-diffusion high-temperature synthesis method (SHS), the heat dissipation dispersion method (XDTM), the contact reaction method, the mixed salt reaction method, and the mechanical alloying method) are all in-situ synthesis. Among them, mechanical alloying, also known as high-energy ball milling, is an important method for the preparation of ultrafine materials.