| All data is for information only------(Home) | |
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| PRODUCT DATA of Wolfram (Tungsten) |
| Material | Wolfram (Tungsten) |
| Precautions | Tungsten is likely to be brittle at room temperature or at lower temperatures and therefore requires careful handling to avoid fracture. |
| Chemical Composition | 100W |
| CAS Registry ID | 7440-33-7 |
| EXPERIENCE IN PRACTICE |
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| Development Status | Special Commercial Product |
| Equivalent Designations | W |
| Space Experience | Fair |
| PHYSICAL PROPERTIES |
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| Atomic Number | 74 |
| Atomic Weight | 184 amu |
| Work Function | 4.55 eV |
| Crystal Structure | Body centered cubic (bcc) |
| Specific Gravity | 19.2 |
| Magnetic Properties | Nonmagnetic |
| ELASTIC PROPERTIES |
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| Tensile Modulus | 411 GPa |
| Bulk Modulus | 311 GPa |
| Poisson Ratio | 0.28 |
| Speed of Sound (longitudinal) | 5180 m/s |
| Speed of Sound (transverse) | 2870 m/s |
| Acoustic Impedance | 99.7 MRayls |
| ELECTRICAL PROPERTIES |
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| Electrical Volume Resistivity | 5.5e-8 ohm.m |
| Electrical Conductivity | 31 %IACS |
| Superconductivity Critical Temperature | -273 °C |
| THERMAL PROPERTIES |
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| Thermal Conductivity | 167 W/m.K |
| Thermal Expansion Coefficient | 4.44 μstrain/°C |
| Specific Heat | 0.138 J/g.K |
| Melting Range | 3400 °C |
| RELEVANT PROPERTIES FOR USE IN SPACE COMMUNITY |
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| Corrosion/Thermal | Tungsten resists water and water vapour at room temperature, but at red heat the metal is oxidised rapidly to WO3 and blue oxide |
| Atmospheric Corrosion | Tungsten is not affected by air at room temperature when the metal is in other than the powder form. Fine-powdered Tungsten is pyrophoric. At 400C to 500C, Tungsten begin to oxidise in air. |
| EMF vs SCE | -0.3 V Remark: Measured in 3.5% NaCl solution Data Quality: Design Data |
| Machinability | Abrasive wheels of silicon carbide are used to machine Tungsten. Light pressure, high tool speed, and an abundance of coolant facilitate the grinding of cutting operations |
| Welding | Oxidation is a problem in the welding of Tungsten |
| Brazing | Tungsten can be brazed using copper, copper-nickel alloys and tantalum (for high T use) |
| Soldering | Silver and soft solder are used to solder Tungsten |