Industrial role of tungsten
2018-09-28
Industrial role of tungsten
The melting point of tungsten is the highest among all metal elements, the density is very high, close to gold, and the hardness of tungsten is also high. For example, the hardness of tungsten carbide is close to that of diamond. In addition, tungsten also has good electrical and thermal conductivity, small expansion coefficient and other characteristics, and thus is widely used in the fields of alloys, electronics, chemicals, etc., among which cemented carbide is the largest consumer of tungsten.
First, the alloy field
1）. Steel
The hardness of tungsten is very high. The density of tungsten is close to that of gold, which can improve the strength, hardness and wear resistance of steel. It is an important alloying element and is widely used in the production of various steels. Common tungsten-containing steels have High-speed steel, tungsten steel, and tungsten-cobalt magnets with high magnetization and coercive force. These steels are mainly used in the manufacture of various tools such as drills, milling cutters, wire drawing dies, negative molds and male molds.
2）. Tungsten carbide-based hard alloy
Tungsten carbides have high wear resistance and refractory properties, and their hardness is close to that of diamonds, so they are often used in some cemented carbides.
3）, heat and wear-resistant alloy
4）. High specific gravity alloy
Second, the field of electronics
Tungsten is widely used in the electronics and power industries due to its high plasticity, low evaporation rate, high melting point and strong electron emission capability. For example, tungsten wire has high luminosity and long service life, so it is widely used in the manufacture of various bulb filaments, such as incandescent lamps, iodine tungsten lamps, etc., and tungsten filaments can also be used to manufacture direct thermal cathodes and gates of electronic oscillating tubes. And a side hot cathode heater in various electronic instruments. The properties of tungsten make it well suited for TIG welding and other electrode materials like this.
Third, the chemical field
Tungsten compounds are commonly used as catalysts and inorganic colors. For example, tungsten disulfide is used as a lubricant and catalyst in the preparation of synthetic gasoline. Bronze-colored tungsten oxide is used in painting, and calcium or magnesium tungsten is commonly used in phosphors.
Fourth, other areas
Since tungsten has a thermal expansion similar to that of borosilicate glass, it is used for glass or metal sealing. Tungsten is low in sensitivity and is therefore used to make high purity tungsten gold jewelry. In addition, tungsten is also used in radiological medicine, and some instruments also use tungsten wire.