Nonferrous Metal
Tungsten is a non-ferrous metal. Metals are usually divided into two categories according to their color and properties: ferrous metals and non-ferrous metals. Ferrous metals mainly refer to iron, manganese, chromium and their alloys, such as steel, pig iron, ferroalloys, cast iron, etc. Metals other than ferrous metals are called non-ferrous metals. Tungsten belongs to the category of non-ferrous metals. The strength and hardness of non-ferrous alloys are generally higher than those of ferrous metals, the resistance is greater than that of ferrous metals, the temperature coefficient of resistance is small, and they have good comprehensive mechanical properties. Therefore, as a non-ferrous metal, tungsten has very high strength and hardness. Due to this characteristic, tungsten cemented carbide, which has high hardness and strong wear resistance, is widely used in cutting tools and mining tools.
Refractory metals
Tungsten is a refractory metal with the highest melting point. Generally, metals with a melting point higher than 1650 °C and a certain amount of reserves, as well as metals with a melting point higher than the melting point of zirconium (1852 °C), are called refractory metals. Typical refractory metals are tungsten, tantalum, molybdenum, niobium, hafnium, chromium, vanadium, zirconium and titanium. As a refractory metal, the most important advantage of tungsten is that it has good high temperature strength, good corrosion resistance to molten alkali metal and vapor, and tungsten only appears oxide volatilization and liquid oxide above 1000°C. However, it also has the disadvantage of having a high plastic-brittle transition temperature and making it difficult to process plastically at room temperature. The refractory metal represented by tungsten has been widely used in metallurgy, chemical industry, electronics, light source, machinery industry and other sectors.
Rare metals
Tungsten is a rare metal. Rare metals usually refer to metals that are found in small quantities or are sparsely distributed in nature. Tungsten is a widely distributed element found in almost all types of rocks, but in low concentrations. The content of tungsten in the earth's crust is 0.001%, and the average content in granite is 1.5×10-6, which makes it very difficult to extract, and can usually only be separated by organic solvent extraction and ion exchange methods. With the progress of science and technology, the development of metallurgical technology, equipment and analysis and testing technology, as well as the expansion of the production scale of rare metals, the purity of tungsten has been continuously improved, the performance has been continuously improved, and the variety has been increasing, thus expanding the application field of tungsten. China is rich in tungsten ore resources, and the output and total export of tungsten account for the first place in the world.
Strategic Metals
Tungsten is a strategic metal. As we all know, rare metals are important strategic resources of the country, and tungsten is a typical rare metal with extremely important uses. It is an important part of contemporary high-tech new materials, and a series of electro-optical materials, special alloys, new functional materials and organometallic compounds all require tungsten with unique properties. Although the amount is not large, it is very important and indispensable. Therefore, it is widely used in contemporary communication technology, electronic computers, aerospace development, medicine and health, photosensitive materials, optoelectronic materials, energy materials and catalyst materials.