Introduction and application scope of titanium powder
Titanium powder refers to a group of metal titanium particles with a size of less than 1mm, which is a loose material, and its performance combines the characteristics of the titanium matrix and the commonality of the powder body. Titanium powder is the same as other powders, and its properties include the chemical properties, physical properties and process properties of the powder. However, titanium powder and other powders have a common physical property that they have a large specific surface, so titanium powder also has a large surface free energy. Therefore, titanium powder is more active than metal titanium, more easily reacted with other elements or compounds, more easily oxidized, flammable, and explosive, and belongs to a kind of dangerous goods. Its purity and various properties largely depend on the preparation method and its process conditions.
Titanium powder and titanium alloy powder are usually light gray, which deepens as the particle size becomes smaller. Coarse powder has metallic luster, micro powder is gray, and ultrafine powder is black. Titanium dihydride powder is usually gray-brown in color and darker than titanium powder. The particle size of titanium powder can be divided into 4 grades artificially. The particle size of 1000-50um is coarse powder, 50-10um is fine powder, 10-0.5um is fine powder, and less than 0.5um is ultra-fine powder. The particle shape of titanium powder is spherical, polygonal, sponge-like and flake-like, and its particle shape is related to the preparation method.
Titanium powder is widely used. Titanium powder is mainly used as a grain refiner for cast aluminum and a deflagration agent for pyrotechnics and fireworks. Grade titanium powder has different uses according to different purity and particle size. It is mainly used as raw material for preparing titanium or titanium-containing alloys by powder metallurgy. Other applications are as electric vacuum getters, raw materials for solid mercury sources in electric vacuums, and surface coating materials. Titanium fillers for plastics and raw materials for various titanium compounds (such as TiB2, TiN, TiC, etc.).
Titanium dihydride powder can be used as ceramic and metal welding agent, pure hydrogen source material and powder metallurgy sintering catalyst.
It is estimated that at present, the annual comprehensive production capacity of various titanium powders including titanium powder in my country has reached several hundred tons, and it has reached thousands of tons in the world.
At present, countries around the world have not formulated national standards for the quality of titanium powder, and only the specifications set by each manufacturer. In general, the quality of titanium powder includes three aspects, namely purity, particle size (or particle size range) and particle shape.
The purity of titanium powder includes titanium content and impurity content. The purity of titanium powder is related to its particle size. For products of the same specification, the smaller the particle size, the lower the purity. Usually, the (coarse) titanium powder containing more than (or equal to) 99% or close to 99% of titanium is called a grade product (if it is a titanium alloy powder, it should include alloy components), and the one with a lower purity than it is called a quasi-grade product. In the grade of titanium powder, in addition to the special purpose requirements, it is generally required to use the oxygen content to classify (the same as the titanium content), that is, the lower the oxygen content, the higher the quality, and the oxygen content is often less than 0.15% is called high-quality titanium powder.