Tungsten carbide is a compound composed of tungsten and carbon. Its hardness is similar to diamond. Its chemical properties are very stable and it is very popular in various industrial fields. Today, Sidi Xiaobian will talk with you about the production method of tungsten carbide.
According to the requirements of tungsten carbide roller size, different sizes of tungsten carbide are used for different purposes. Carbide cutting tools, such as cutting machine blade V-shaped cutting tools, fine alloy with ultrafine subfine tungsten carbide particles. Coarse alloy using medium particle tungsten carbide; The alloy for gravity cutting and heavy cutting is made of medium coarse tungsten carbide. The rock used for mining tools has high hardness and impact loads and uses coarse tungsten carbide. Small rock impact, small impact load, with medium particle tungsten carbide as raw material wear-resistant parts; In emphasizing wear resistance, pressure resistance and surface smoothness, ultrafine ultrafine medium particle tungsten carbide is used as raw material. The impact tool mainly uses medium and coarse tungsten carbide raw material.
Tungsten carbide has a theoretical carbon content of 6.128% (50% atomic). When the carbon content of tungsten carbide is greater than the theoretical carbon content, free carbon appears in tungsten carbide. The presence of free carbon makes the surrounding tungsten carbide particles grow larger during sintering, resulting in uneven cemented carbide particles. Tungsten carbide generally requires high bound carbon (≥6.07%) and free carbon (≤0.05%), while total carbon depends on the production process and application range of cemented carbide.
Under normal conditions, the total carbon of vacuum sintering tungsten carbide by paraffin method is mainly determined by the total oxygen content of briquette before sintering. Part of the oxygen content increased by 0.75 part, that is, the total carbon of tungsten carbide =6.13%+ oxygen content %×0.75 (assuming that there is a neutral atmosphere in sintering furnace, in fact, the total carbon of tungsten carbide in most vacuum furnaces is less than the calculated value) [4] The total carbon content of China’s tungsten carbide can be roughly divided into three paraffin processes.
Vacuum sintered tungsten carbide has a total carbon content of about 6.18±0.03% (free carbon will increase). The total carbon content of paraffin wax hydrogen sintering tungsten carbide is 6.13±0.03%. The total carbon content of rubber hydrogen sintering tungsten carbide is 5.90±0.03%. These processes sometimes alternate. Therefore, the total carbon content of tungsten carbide is determined according to specific conditions.
Post time: May-04-2023
