Metal tungsten in the form of Spherical tungsten powder is the raw material for preparing tungsten processing materials, tungsten alloys and tungsten products. It is a gray-black metal (body-centered cubic crystal) with metallic luster. The melting point is 3400°C. The boiling point is 5555°C. The hardness of tungsten is the hardest among metals. The hardness of the sintered tungsten rod is 200-250, and the hardness of the tungsten rod hammered with a hammer is 350-400. A mixed acid dissolved in nitric acid, melted with a mixture of sodium hydroxide and sodium carbonate. Slightly soluble in nitric acid, sulfuric acid and aqua regia; insoluble in water and potassium hydroxide. There are two variants of tungsten, a and B. At standard temperature and atmospheric pressure, type a is a stable body-centered cubic structure. Type B tungsten can only appear in the presence of oxygen. It is stable below 630℃, and transforms into α tungsten above 630℃. This process is irreversible.

In addition to the hydrogen reduction method, Spherical tungsten powder is prepared by the tungsten oxide carbon reduction method used earlier, and the reduction temperature is higher than 1050°C. The purity of tungsten powder obtained by this method is low. In addition, research work on reducing tungsten oxide with metal aluminum, calcium, zinc, etc. is also underway. For special applications that require high-purity, ultra-fine particle size tungsten powder, a tungsten chloride hydrogen reduction method has been developed, and the particle size of the obtained tungsten powder can be less than 0.05μm.

In addition to certain requirements for the impurity content in Spherical tungsten powder, the oxygen content must also be controlled within a certain range. The particle size of commonly used tungsten powder is generally Fisher's average particle size of 2-10μm. The tungsten powder has a polygonal particle shape. In addition, the specific surface area, bulk density and tap density of tungsten powder also vary within a certain range. The performance of tungsten powder directly affects the production of tungsten materials and the quality of tungsten powder metallurgical products, especially the impact of purity and particle size. Tungsten powder is classified according to its purity, particle size and purpose.

Spherical tungsten powder is the main raw material for processing powder metallurgy tungsten products and tungsten alloys. Pure tungsten powder can be made into processed materials such as wires, rods, pipes, plates, and products with a certain shape. Tungsten powder mixed with other metal powders can be made into various tungsten alloys, such as tungsten-molybdenum alloy, tungsten rhenium alloy, tungsten copper alloy and high-density tungsten alloy. Another important application of tungsten powder is to make tungsten carbide powder to prepare cemented carbide tools, such as turning tools, milling cutters, drill bits and molds.