Tungsten metal in the family of non-ferrous metals, tungsten to maintain "high temperature champion" title for up to a hundred years. The world's first discovery of tungsten is the Swedish chemist. He first decomposed tungstic acid with acid in 1781, and obtained tungsten elements. Then, after a period of hard study, Tungsten Metals only in 1848 produced a pure metal tungsten. Pure tungsten silver white, very beautiful, the proportion of up to 19.1t / m3.
Tungsten metal performance superior
Tungsten chemical stability, even in the case of heating, and hydrochloric acid, sulfuric acid does not work, even in the king of water will not be dissolved. Tungsten extremely high temperature, known as the most refractory metal in nature, the melting point of up to 3410 ℃; tungsten hardness in the metal among the best, Tungsten Metals only heated to a high temperature, in order to pressure processing.
Tungsten metal is unique
Tungsten has many unique uses, such as tungsten, which can be made of tungsten steel. With tungsten steel manufacturing tools, than the strength of ordinary steel tools several times or even several times; with tungsten steel manufacturing barrels, barrels, in continuous shooting, even if the barrel was shot friction, can still maintain good flexibility And mechanical strength. In the metal cutting machine, with tungsten steel to do turning, the temperature up to 1000 ℃ still hard as before. Tungsten-containing tungsten-chromium-cobalt alloy steel containing 3% to 15% of the tungsten-chromium-cobalt alloy is sprayed or welded to the surface of ordinary steel parts. It is equivalent to putting hard "armor" into the part, which is resistant to temperature and corrosion. Wear, Tungsten Metals life can be extended several times. Due to the superior characteristics of tungsten steel and wide use, the world's annual production of tungsten, 90% are used to manufacture tungsten steel.
Tungsten metal is highly plastic. A 1 kg of tungsten rods, can be pulled into a length of about 400 km, only 1% diameter of the filaments. This filament in the high temperature environment of 3000 ℃, still has a certain strength, and high luminous efficiency, long life, is to create a variety of light bulbs good material. Incandescent, iodine tungsten lamp, and even the world's most innovative bulbs, lamps, are made of tungsten wire.
The United States has used a new type of solid fuel, so that the rocket gas temperature exceeds 3000 ℃. In this case, the most difficult to melt the tungsten nozzle is also difficult to parry. Tungsten Metals Scientists have studied the manufacture of a new type of tungsten alloy - "self-cooled silver-permeable porous tungsten alloy". When the rocket in the air high-speed flight, with this new alloy made of high temperature and high pressure nozzle, will continue to spray sparkling flames. The silver that penetrates the surface of the nozzle first evaporates at high temperatures and absorbs heat while evaporating. In this way, to achieve the purpose of automatic cooling and to prevent the temperature rise is too high, so that by 3000 ℃ high temperature baked nozzle, still able to maintain the original traits.