First off I'd better give you a little clip from the manufacturer's
web site so everyone knows what this stuff is...
"PocoFoam is produced through a patented foaming process
that creates a structure of highly graphitic aligned ligaments within the
foam's cell walls. These ligaments are the key to the material's high thermal
conductivity. They perform like high performance graphite fibers, wicking
heat away from its' source. PocoFoam has proven to be 3 to 9 times more thermally
conductive than typical lightweight carbon foams. PocoFoam also demonstrates
thermal conductivity up to 10 times higher than metallic foam materials, such
as aluminum foam. Since this exciting new material is an advanced open cell
foam, weight savings are significant when compared to conventional thermal
management materials like aluminum or copper. When compared to aluminum, samples
of graphite foam are five times lighter yet demonstrate equal or greater thermal
conductivity. In addition, with an active service area of more than 4 m 2
/g, PocoFoam's heat transfer efficiencies have been shown in laboratory testing
to be significantly greater than aluminum or copper. " -- sound interesting?
I originally heard about PocoFoam March 2000. Their web site
was 1 page with an e-mail link and I contacted them to find out more. Of course
my first question was "can I get a sample?". They replied that they were just
entering production and unfortunately the 2"x2"x2" engineering sample I requested
would cost around $480 usd. at the time. Seeing how I was running Pr0n
for background at UpAvolt at the time, they didn't see fit to mail me 500
bucks worth of carbon. None the less they were willing to answer my questions
and when they got their web based customer service set up they gave me an
account. I had been asking them questions frequently throughout the year as
I pursued other projects, and merged sites with Spode.
After over a year of pestering them for an engineering sample they finally
gave in and sent me their "standard" hunk, 5/8"x2"x2". Here's what it
looks like.
This stuff reminds you of that black "stink stone" sanding block that smells
like sulphur. It is really fragile and weighs almost nothing. It's hard to
believe that with such small pores that the air would pass freely through
it - but when you blew though it there was no resistance.
Unfortunately it wasn't as much as I needed to make an air cooler
with like I originally hoped to, but I was glad to have some to work with.
My plan was to use this foam, with it's massive internal surface area as a
sink in a water block and to force the water through the foam that would in
turn be epoxied to a copper plate. To make sure I wasn't just cooling the
copper with the water I used 0.025" sheet metal for the plate, it is too thin
to transfer the heat very far from the die. I also used acrylic for the body
so as not to transfer heat to the water. (I wasn't going for the best
possible design, it was more to test the foam's ability to transfer heat.
Bear in mind that these are prototypes and I am in no way a
machinist :)
Here's my first prototype - the idea was to do it on a small
scale to see if it was feasible (without burning up my $200+ hunk of foam
on a bad idea). The actual foam is 3/4"x3/4"x5/8" and you can kinda
see the holes and how the water must pass through the foam to exit.
I hooked it up to my Duron 800 using my trash
can radiator and set it at stock speed/voltage and gave the button a poke.
As soon as I was in windows I checked the temps, 42c not too bad, after 10
minutes at idle - 47c, still not too bad. I fired up some AHL and started
fraggin, after 2 maps (40 minutes) I pulled out and the temp was up to 54c.
At first I was disappointed - BUT WAIT! this is just the "mini" tester version!!
