Tungsten Carbide Coated Wear Resistant Material

Tungsten carbide is a compound composed of tungsten and carbon. Its hardness is similar to that of diamond. It has good hardness and stable properties. It is not only used in cemented carbide, but also as wear-resistant and corrosion-resistant materials for iron-based or nickel-based alloys.

When strengthening iron-based or nickel-based alloys, tungsten carbide coated powder is sprayed onto the surface of alloys by spraying equipment, and a film is formed on the surface of alloys to protect the alloys. However, tungsten carbide powder used in traditional spraying is usually made into wear-resistant materials by high temperature sintering method, which is subjected to process. The limitation of tungsten carbide can not give full play to the high hardness and stable properties of tungsten carbide, and can not protect the alloy for a long time.

In view of the shortcomings of the existing technology, some scholars have sought solutions on tungsten carbide powder and prepared a tungsten carbide coated wear-resistant material by chemical vapor deposition. The preparation steps are as follows:

(1)Ultrafine niobium, molybdenum powder, nickel powder, nano-titanium oxide, nano-chromium oxide and silicon carbide were weighed according to the percentage of quality.

(2)After mixing all the components of the matrix evenly, the mixed powder is put into the high temperature furnace and burned at 500-900 ℃ for 1-3 H.

(3)After scorching, it is cooled to room temperature, removed and put into a ball mill for grinding. The average particle size of the powder is 0.1-10um, and then taken out for drying.

(4)Put the powder into the chemical vapor deposition reaction chamber, vacuum to 10-100 Pa, preheat to 500-700 ℃, take tungsten fluoride and methane as precursors, and inject argon. The rotating rate of the reaction chamber is 30-60 r/min and the reaction time is 15-60 min. After the reaction, it will be cooled to room temperature and taken out.

(5)The coated powder is mixed evenly and then put into the mould for high temperature scorching. The temperature is 1250-1500 ℃ and the time is 1-3h. When it is cooled to room temperature, the wear-resistant material coated with tungsten carbide is obtained.

Using chemical vapor deposition (CVD) technology, tungsten carbide nano-film was formed by coating tungsten carbide on the matrix powder, using tungsten fluoride and methane as precursors and controlling the gas flow ratio (C/W ratio) of methane and tungsten fluoride, and then high performance wear resistant materials were prepared by high temperature method. The prepared tungsten carbide coated wear-resistant material has the characteristics of high density, high wear resistance and high hardness, and has excellent corrosion and weathering resistance. It can be directly used as wear-resistant material, or crushed to the corresponding fineness, and used as wear-resistant filler.

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