[quote author=Jack Christensen link=topic=168993.msg1257399#msg1257399 date=1369794791]
Regarding the density calculations, if it doesn't come close to copper, how close is it to aluminum? Al is a much more common material for heatsinks than Cu.[/quote]
I am not sure what cheap metal you can mix with copper, but if they used copper+aluminum (but aluminum melting point it is very low ~650C vs ~1080C, so I am not sure a mix will be homogeneous), then is 64% copper
robtillaart:
Is it not enough to heat it up to a certain temperature and measure the cool down temperature versus time?
from my head it would be some negative exponential function likeTt = Te + c1 * exp(c2 * -t). // Tt is temp at time t; Te is T environment, the temp it cools down to, c1 and c2 are constants depending on material form etc.
and c1 was the HTC? (I do not recall anymore)
Excel could help you find the equation if you have the sample data.
I want to use a similar formula I found in wikipedia, but then I was wondering the many variables the material form will have, it the shape was just a box, then it is easy, dissipation surfaces are the layers, but having these "pegs" increase the surface. The aluminium ones have another design:
And the copper ones seems less friendly with "directed wind flow":
Anyway copper is way too soft to shape it in thin shapes. To simplify the equation I can just consider the heatsink as a rectangle, so what is left is to determine how to apply the heat, and where to measure. Because for sure the contact surface with the heating element changes a lot the transference. The ceramic peltier cells are perfectly flat btw.