Is there necessarily a relation between the specific heat capacity of a material and its melting point? Can you have a material that has a low specific heat capacity but have a high melting point?
The reason I ask this is because I want to make a cooker of sorts, but don’t know what to make it out of.
Something that I can heat up, with a lowish specific heat capacity, that can resist melting below 2000 degrees celsius (approximately).
Thanks
Mapes
Aug29-08, 09:38 AM
You'd expect the specific heat capacity to increase with temperature, since the molar heat capacity of metals is similar (~25 J/mol-K) and denser elements generally have a higher melting temperature.
Only a handful of elements are still solid at 2000°C. Tungsten seems to be a good choice.
Borek
Aug29-08, 10:33 AM
What about carbon?
chemisttree
Aug29-08, 11:31 PM
Try hafnium carbide or yttrium-stabilized zirconia.
turnip
Sep6-08, 09:04 AM
thank you for your replys and suggestions!
Borek: I had considered carbon, but wouldn't it react with the atmsophere and desintigrate rather quickly?
Chemisttree and Mapes: would these compounds be easy enough to get hold of in a reasonable size?
Borek
Sep6-08, 12:20 PM
I had considered carbon, but wouldn't it react with the atmsophere and desintigrate rather quickly?
Yes and no. Carbon fibers are used in many applications, including those high temp ones.
turnip
Sep8-08, 03:01 AM
Yes and no. Carbon fibers are used in many applications, including those high temp ones.
Okay, thanks!
chemisttree
Sep8-08, 11:11 AM
If you try to use carbon fiber it will catch on fire and burn up the first time you use it. Carbon is NOT used in atmospheric high temperature applications without cladding. The RCC (Reinforced Carbon-carbon Composite) used on the shuttle tiles is clad in silicon carbide for example to prevent burnup during reentry.
Yttrium-stabilized zircon can be found here (http://www.americanelements.com/ysz.html) and elswhere. Google it yourself. Same goes for hafnium carbide (http://www.micronmetals.com/hafnium_carbide.htm)
Borek
Sep8-08, 11:41 AM
Carbon is NOT used in atmospheric high temperature applications without cladding.
Just for the record: I have never meant bare carbon can be used.