Hafnium

feature

Hafnium — heat-resistant heavy metal with a silvery-white color, number 72 in the periodic table of elements, where indicated by the symbol Hf. The name comes from the obsolete name of Copenhagen — Hafnia. Metallic hafnium is produced from zirconium ores. Its production is about 70 tons annually — is proportional to the extraction of Zr. The richest deposits in Australia and South Africa. Hafnium has a hexagonal structure of the crystal lattice, the density for 13, 31 g/cm3. The melting point of 2150 °C, t° boiling point of 5400 °C, with a valence of +4. The capture cross section of thermal neutrons by the hafnium to 500 times wider than that of zirconium — 100 barn compared to the 0.2 barn. Zirconium is used for nuclear energy, purified from hafnium impurities. Natural 174th isotope of hafnium, shows weak alpha activity.

use

Nuclear energy. A wide cross-section of capture of thermal neutrons allows the use of Hf in the control rods of nuclear boilers, and also for spectralite and glass, check ionizing radiation. The alloy of this metal with the tantalum and tungsten — the best fuel in the gas-phase nuclear reactors.

Optics. Due to the heat resistance and high refractive index of 4-valent oxide and hafnium fluoride is used in the glass composition for multilayer x-ray astronomical mirrors, fiber optics, night vision devices.

Electronics and electrical engineering. The minimum output energy of electrons (3,53 eV) and heat resistance can produce hafnium cathodes for high-vacuum tubes and electron guns and thermionic generators. These same qualities of hafnium important in the production of electrodes for welding in argon. Hafnium electrodes for welding of low carbon steel in carbon dioxide atmosphere is almost 4 times more efficient than tungsten. Doping with tantalum, 20% tungsten and 2% additives and 05% silver, chromium, caesium have a large economic effect in oxygen-flame or air plasma cutting of metals. In electroforming using the hafnium wire is carried out the controlled decomposition of compounds by galvanic current. Anti-corrosion coating is also applied using the hafnium wire in vacuum.

Doping. Supplement 1% Hf to aluminum gives a very durable alloy with a cross section of the grains is about 0,045 µm, which has high tensile strength under dynamic and static loads, as well as improved vibration resistance. Hafnium strengthens cobalt alloys relevant to the chemical and processing industries. Alloying of Nickel with hafnium increases the strength and the corrosion resistance and also improves weldability and hardens the weld.

Composite Hf. They are relevant as an extremely wear resistant coating. Refractory HfC (t° PL. 3890°C) is indispensable in the design of gas-phase nuclear installations and in the production of rocket nozzles. Nickel doped HfB2, is used as an extremely wear resistant coating. Alloy carbides of hafnium and tantalum of 1:4 is considered the most heat resistant of known materials (t° PL 4216°C).

Mechanical engineering. Titanium-hafnium alloys are in parts manufacturing ship engines. Alloying of steels by hafnium and tantalum dramatically increases the resistance to oxidation and teploobmenu (thermal shocks). This has resulted in materials jet equipment: gas rudders, nozzles.

Other areas. Hafnium is used in alloys, for heavy duty permanent magnets. Dielectrics based on HfO2 displace oxide of silicon microelectronics, allowing you to achieve a much higher density of elements in chips. Alloys of hafnium and scandium is used in microelectronics to obtain resistive films special properties.

BUY AT best PRICE

Reasonable cost of rare and refractory metals, which is based bets on the London stock exchange of nonferrous metals, a wide variety of products in stock, LLC «_" will allow any buyer to make the optimal choice. High quality hafnium semi-finished products, full compliance with the requirements of the state normative documents and technical conditions for the supply — the main criterion, which adheres to our company in working with clients. OOO «_" is a reliable partner in the metal market, and the exact conformity to the declared characteristics of the products, reasonable prices and convenient delivery method is the additional benefit of working with us.