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Tungsten Metal History
Tungsten Metal
Tungsten Metal History |
It was not until 1781 that Carl Wilhelm Scheele, a fellow Swede, ascertained that a new acid could be made from scheelite (at the time named tungstenite): tungstic acid. He and Torbern Bergman suggested that it could be possible to obtain a new metal by reducing this acid
In 1783, Independent of Scheele, two Spanish chemists, the brothers Elhuyar de Suvisa, first reduced the mineral wolframite to tungsten metal. They found an acid made from wolframite that was identical to tungstic acid. Later the brothers succeeded in isolating tungsten through reduction of this acid with charcoal. They are credited with the discovery of the element.
Jöns Jacob Berzelius (1816) and later also Friedrich Wöhler (1824) described the oxides and bronzes of tungsten and gave the new metal the name "wolfram". While this established itself in Germany and Scandinavia, the Anglo-Saxon countries preferred Cronstedt's "tungsten".
In 1821, K.C. von Leonhard proposed the name "Scheelite" for the mineral CaWO4.
The first industrial application of tungsten metal was the alloying and hardening of steels late in the 19th century. Rapid growth and widespread application followed the invention, and the launch of high speed steels by Bethlehem Steel took place in 1900 at the Paris World Exhibition.
The second important breakthrough in tungsten metal applications was made by W. D. Coolidge in 1903. Coolidge succeeded in preparing a ductile tungsten wire by doping tungsten oxide before reduction. The resulting metal powder was pressed, sintered and forged to thin rods. Very thin wire was then drawn from these rods. This was the beginning of tungsten powder metallurgy, which was instrumental in the rapid development of the lamp industry.
The year 1923 is the next important milestone in the chronology of tungsten. It marks the invention of hardmetal (combining WC and Cobalt by liquid phase sintering) by K. Schröter and the corresponding application for a patent which was granted to Osram Studiengesellschaft in Berlin and licensed to Krupp in Essen in 1926. Nowadays, hardmetal (cemented carbide/tungsten carbide) is the main application for tungsten metal.
In World War II, tungsten metal played a significant role in background political dealings. Portugal, as the main European source of tungsten, was put under pressure from both sides, because of its sources of wolframite ore. The resistance to high temperatures, as well as the extreme strength of tungsten alloys, made tungsten metal into a very important raw material for the weaponry industry.
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More Related Subjects: Tungsten metal introduction Tungsten Metal Processing |