Properties of Tungsten
The word tungsten means "heavy stone" in Swedish. The chemical symbol for tungsten is W which stands for wolfram. The name came from medieval German smelters who found that tin ores containing tungsten had a much lower yield. It was said that the tungsten devoured the tin "like a wolf". Pure tungsten metal was first isolated by two Spanish chemists, the de Elhujar brothers in 1783. Tungsten is a greyish-white lustrous metal, which is a solid at room temperature. Tungsten has the highest melting point and lowest vapor pressure of all metals, and at temperatures over 1650°C has the highest tensile strength. It has excellent corrosion resistance and is attacked only slightly by most mineral acids.
Information on tungsten containing minerals
| Atomic Number | 74 |
| Atomic Weight | 183.86 |
| Group Number | 6 |
| Electron Configuration | 1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4f14, 5s2, 5p6, 5d4, 6s2 |
| CAS Registry Number | 7440-33-7 |
| Atomic Volume | 9.53 |
| Lattice Type | Body Centered Cube |
| Lattice Constant at 20 ºC, Angstroms | 3.1585 |
| Natural Isotopes | 180, 182, 183, 184, 186 |
| Density @ 20 ºC (gm/cc) | 19.3 |
| Density @ 20 ºC (lb./cu. in.) | 0.697 |
| Melting Point ºC | 3410 |
| Boiling Point ºC | 5530 |
| Linear Coefficient of Expansion per ºC | 4.3 x 10E-6 |
| Thermal Conductivity @ 20 ºC (cal/cm/ºC/sec) | 0.40 |
| Specific Heat @ 20 ºC (cal/gram/ºC) | 0.032 |
| Electronegativity (eV) Pauling | 2.36 |
| Electronegativity (eV) Sanderson | 0.98 |
| Electronegativity (eV) Allred Rochow | 1.40 |
| Electrical Conductivity, % IACS | 31 |
| Electrical Resistivity @ 20 ºC (microhm-cm) | 5.5 |
| Electrical Resistivity @ 227 ºC (microhm-cm) | 10.5 |
| Electrical Resistivity @ 727 ºC (microhm-cm) | 24.3 |
| Electrical Resistivity @ 1727 ºC (microhm-cm) | 55.7 |
| Electrical Resistivity @ 2727 ºC (microhm-cm) | 90.4 |
| Electrical Resistivity @ 3227 ºC (microhm-cm) | 108.5 |
| Temperature Coefficient of Electrical Resistivity Per ºC (0 - 100 ºC) | 0.0046 |
| Tensile Strength @ Room Temp., psi | 100,000 - 500,000 |
| Tensile Strength @ 500 ºC, psi | 75,000 - 200,000 |
| Tensile Strength @ 1000 ºC, psi | 50,000 - 75,000 |
| Poisson's Ratio | 0.284 |
| Hardness (Mineral) | 7.5 |
| Hardness (Vickers) | 3430 |
| Hardness (Brinell) | 2570 |
| Reflectivity | 62% |
| Total Emissivity @ 1500 ºC | 0.23 |
| Total Emissivity @ 2000 ºC | 0.28 |
| Working Temperature, ºC | <1700 |
| Recrystallization Temperature, ºC | 1300 - 1500 |
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