Thermal conductivity of pure tungsten at various temperatures

Thermal conductivity of pure tungsten at various temperatures

Junjie Chen

Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail], Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China

Tungsten, or wolfram, is a chemical element with the atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include scheelite and wolframite, the latter lending the element its alternate name. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all known elements barring carbon. It also has the highest boiling point. Its density is 19.30 grams per cubic centimetre, comparable with that of uranium and gold, and much higher than that of lead. Polycrystalline tungsten is an intrinsically brittle and hard material, making it difficult to work. However, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw. Tungsten occurs in many alloys, which have numerous applications, including incandescent light bulb filaments, X-ray tubes, electrodes in gas tungsten arc welding, superalloys, and radiation shielding. Tungsten's hardness and high density make it suitable for military applications in penetrating projectiles. Tungsten compounds are often used as industrial catalysts. In its raw form, tungsten is a hard steel-grey metal that is often brittle and hard to work. Purified, monocrystalline tungsten retains its hardness, and becomes malleable enough that it can be worked easily. It is worked by forging, drawing, or extruding but it is more commonly formed by sintering. Of all metals in pure form, tungsten has the highest melting point, lowest vapor pressure, and the highest tensile strength.

Thermodynamic temperature (degrees kelvin), Thermal conductivity (watts per meter-kelvin)

10          9710

100        208

293        173

1000             118

2000             98