Characteristics and applications of tungsten, pincers, tantalum, niobium and precious metals and their alloys

Tungsten, tongs, tantalum, niobium and their alloys are characterized by high melting point, but the common disadvantage is poor oxidation resistance at high temperature and brittleness at low temperature. Pure tungsten melting point of 3410 ℃, 1300 ℃ or so still has high strength, and tungsten alloy at 1800 ℃ or so also has high strength, good thermal shock ability; Commonly used for rocket nozzle, lamp tungsten wire, electric contact, high temperature heating body. Pure aluminium melting point of 26 l0 ℃, 1800 ℃ still has high strength, commonly used as the working temperature of 1700 ℃ heating element, tube cathode, grid and high voltage rectifier components, moulds, nuclear reactor coating material, core material, high temperature and corrosion resistant materials such as glass melting kiln electrode. Tantalum has good comprehensive properties of physics, mechanics and technology. Its oxide film is dense and corrosion-resistant. It can be used as aerospace high-temperature structural material and medical science. In addition to the general high melting point metal characteristics of niobium, the plasticity is particularly good, adding strengthening elements still does not reduce its plasticity, excellent welding performance.