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Updated September
21, 2004
Tungsten gets its periodic symbol
from its German name, Wolfram. Tungsten is a "refractory"
metal, meaning that you have to heat the hell out of it before it
melts. This is what allows it to be used as lightbulb filaments.
This property also allows tungsten to be used in high-temperature
cofired ceramics, because the ceramics melt below the temperature
that tunsten vaporizies or catches on fire. Due to its relatively
high resistivity, co-fired ceramic feed through plugs employing
tungsten have appreciable RF loss. But if they used gold conductors,
they would have even higher loss because the gold would have burned
away during firing.
| Formula or Composition: |
W |
| Bulk Resistivity: |
5.6 -cm |
| Temperature
Coefficient of Resistivity (TCR): |
ppm/°C |
| Mass Density:
|
19.3 gr/cc |
| Heat Capacity:
|
135.9 J/kg/°C |
| Thermal Conductivity
(k): |
169 W/m°C |
| Temperature
Coefficient of Expansion (TCE): |
4.5 ppm/°C
|
| Melting Point,
°C: |
3410 °C |
| Melting Point,
°F: |
6170 °F |
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