Machining and Handling of Tungsten and Alloys

Tungsten is a refractory metal (the highest of all known pure metals) with extraordinary heat and wear resistance. In addition to its very high melting temperature, W is known for its high density, high elastic modulus, high thermal conductivity, and excellent mechanical properties at high temperatures. W is an ideal material for high temperature structures in fusion energy and other applications.

The rich history of W, from the discovery of its ores and compounds to later important technological discoveries, stimulated widespread early use. The discovery of the W mineral dates back to the tin mines of medieval Saxony-Bohemia and Cornwall, well before the separation of the element itself. While the separation of W was first proposed by Torbern Bergmann in 1781, Juan José de Elhuyar and his brother Fausto prepared the metal in 1783 by reducing tungstic acid with charcoal powder. The metal was also named wolframite, which is still its official name today in German and Swedish.

The earliest application of W was as an alloying element to produce specialty steels. It soon gained prominence as the filament for incandescent lamps, replacing carbon filaments. Since then, the material has been widely adopted in various fields, including aerospace, automotive, electronics, medicine, military, chemistry and sports. Applications include heating wires, electron emitters, heat sinks, heating elements and radiation shielding in high temperature furnaces, kinetic energy penetrators, balance weights in racing and aerospace, rotors in the watch industry, heavy duty electrical contact materials and welding, Plasma and X-ray electrodes, etc.

Although the properties of W are beneficial for its applications, properties such as W ductility and high melting point also lead to some challenges in the large-scale fabrication of components made of W and its alloys, limiting the production of these complex geometries.