new material for a heat sink
new material for a heat sink
(OP)
hi there
at the moment we use a copper chrome disk (concave and convex lens shaped) to transfer the heat from a cast iron base to a pyrex cap, the curvature of the cap and the base are different so the copper has a varying thickness.
what is happening is that the caps are cracking, and the coppers expansion is a consideration.
what im looking for are aternatives to the copper chrome, i need a high thermal conductivity and a low thermal expansion.
the caopper insert has at the moment a
COE = 18x10-6/degC
Thermal conductivity = 300w/m degC
any help would be greatly appereciated :)
at the moment we use a copper chrome disk (concave and convex lens shaped) to transfer the heat from a cast iron base to a pyrex cap, the curvature of the cap and the base are different so the copper has a varying thickness.
what is happening is that the caps are cracking, and the coppers expansion is a consideration.
what im looking for are aternatives to the copper chrome, i need a high thermal conductivity and a low thermal expansion.
the caopper insert has at the moment a
COE = 18x10-6/degC
Thermal conductivity = 300w/m degC
any help would be greatly appereciated :)





RE: new material for a heat sink
Both are easy to form, so can make thinner than the copper to compensate for lower conductivity.
RE: new material for a heat sink
basically use a lower conductiviy material than copper.
RE: new material for a heat sink
If the Pyrex cap is breaking due to mechanical stress, i.e., from the male copper part expanding inside a female cap, maybe you should change the design. Would a porcelein coating on the cast iron satisfy your requirements (chemical resistance? electrical insulator)?
RE: new material for a heat sink
kenvlach, is fused sillica not quite expensive? and porcelin i have not thought about that. interesting
RE: new material for a heat sink
Molybdenum 5 150
Tungsten 5.5 200
copper-tungsten 8.5 210
copper-molybdenum 7.0 150
Ceramics:
aluminum nitride 4.6 190
silicon carbide 3 130