Graphite an amazing heat conductor?

[Nemeskal]

Alright a friend told me a while ago that he had heard/read somewhere write all over your cpu with pencil then it will be ultra cool. I then did a google search but to no avail. Nothing about pencil lead cooling a CPU. I was just browsing to see what material had the highest heat conductivity and i came across this site http://hypertextbook.com/physics/thermal/conduction/ . Graphite owns everything at 1950 as compared to copper's 401. Now is there something i am not getting here or should we all go and cover our cpus with pencil lead?
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[Google]

[mogur]

Thermal conductivity is determined by the crystalline structure of the material. The more uniform the structure, the higher the conductivity. That's why diamond is the most conductive of all. But before you get married to your heatsink, there are other factors that must be considered. One is that even finely finished metallic surfaces only provide about 1% actual contact, the rest of this interstital area is microscopic pits and valleys. Throwing diamond powder in there will be very conductive, but wouldn't increase the area of contact much at all, and probably would actually increase the distance between the two surfaces. That's why silicone paste, which is only an average performing conductor, provides better heat transfer due to its ability to conform to the surface irregularities and vastly increase the contact area. A combination of zinc oxide (that's why it looks like white nose grease) and silicone is often used, and is relatively cheap. Marginally better are the high end pastes with silver and/or other very conductive metal compounds embedded in a silicone paste.

I'm getting to your pencil idea, now. Graphite, unlike diamond, has a crystalline structure in the form of sheets. It is very conductive parallel to the surface of these sheets, but is a relatively poor conductor perpendicular to them. If you could manage to align the graphite structure perpendicular to the mating surfaces, you might find it to be an excellent thermal conductor. But that won't happen if you rub a pencil over the surface of the heatsink. On the other hand, I'm just making this stuff up (I prefer to call it educated guessing), so you should feel free to try your ideas out, and I'll just make up some other theories to fit whatever facts that you discover.

[JayDubya]

mogur seems to know what he is talking about. there are many, many types of graphite. the pencil lead graphite seems to be the most fun! run about 5+v of dc current at .1+amps. it won't hurt you but the graphite experiences awesome reprocussions.
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JayDubya aka JW Jay JD ^> ﺵ