Alternative materials discussion (carbon, diamond, plastics, etc...)

[Kayin]

We're examining carbon blocks right now, but doping a thermally conductive ceramic could make the fastest repeatable test subjects.

I showed off graphene nanoplatelets, I wonder if diamond powder would do the same in matrix...

http://cgi.ebay.com/DIAMOND-POWDER-25-CARAT-LOTS_W0QQitemZ320330697571QQcmdZViewItemQQptZLH_De faultDomain_0?hash=item320330697571&_trksid=p3286.c0.m14&_trkparms=72%3A1209%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

At any rate, we can use this to make our own diamond TIM, too.

[ballz0r]

Ultra high thermal conductivity polymer composites (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWD-44YVK83-K&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=a1fd9194371f146afd95dff5dbe967d4)

Epoxy composites based on vapor grown carbon fiber (VGCF) were fabricated and analyzed for room temperature thermophysical properties. An unprecedented high thermal conductivity of 695 W/m K for polymer matrix composites was obtained. The densities of all the composites are lower than 1.5 g/cc. In addition the high value of coefficient of thermal expansion (CTE) of the polymer material was largely reduced by the incorporation of VGCF. Also, unlike metal matrix composite (MMC), the epoxy composite has an electrically insulating surface. Based on the composite thermal conductivities, the room temperature thermal conductivity of VGCF, heat-treated at 2600°C, was estimated to be 1260 W/m K. Furthermore, the longitudinal CTE of the heat-treated VGCF was determined, for the first time, to be −1.5 ppm/K.
695 W/m k!!!! pure copper is 386

[ballz0r]

Heat is conducted in metals, according to current theory, by lattice waves,
phonons, and free (or valence) electrons. In a non-metal, heat is
conducted only by phonons. (A phonon is equivalent to one quantum of
energy in the form of a thermoelastic wave of fixed frequency. In this
sense, a phonon is analogous to the concept of a photon in electromagnetic
radiation theory.) Because there are three methods of heat transport in
metals, compared with only one in non-metals, one would expect that metals
would be better conductors of heat than non-metals.
The transport of heat through a metal is affected by the structure of the
metal. A single pure crystal of metal will conduct heat much better than a
large number of very small crystals because of scattering of the phonons at
the crystal boundaries. Likewise, if you alloy a metal, the differences in
sizes of metal atoms will cause a large decrease in thermal conductivity.
Mechanical damage to a metal structure by cold working or radiation will
also decrease the conductivity of the metal.
Based upon these considerations, pure copper and silver have the highest
thermal conductivity of the metals. In 1923, a German named Schott
measured the thermal conductivity of a single crystal of copper at 12,200
Watts per meter Kelvin (W/mK) at a temperature of 20.8 K. However, at room
temperature, commercially pure copper typically has a conductivity of about
387 W/mK.
The material with the highest thermal conductivity is the most pure, single
crystal form of carbon, which we call a diamond. When you want to verify
if a diamond is real or not, thermal conductivity is an infallible method.
The thermal conductivity of diamonds is around 1200 W/mK. As a result,
there is interest in learning how to grow diamond films thick enough and
cheaply enough to allow them to be used for thermal management. Other
materials with high conductivity are certain other forms of carbon, such as
high purity graphite fibers and pyrolytic graphite. As you might expect,
both have very high chemical purity and large crystalline structures.


thought this was an interesting read

[ballz0r]

http://cgi.ebay.com/DIAMOND-POWDER-25-CARAT-LOTS_W0QQitemZ320330697571QQcmdZViewItemQQptZLH_De faultDomain_0?hash=item320330697571&_trksid=p3286.c0.m14&_trkparms=72%3A1209%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

At any rate, we can use this to make our own diamond TIM, too.


im locked out of ebay at work... can someone cut and paste some info on this to here?

[just a noob]

im locked out of ebay at work... can someone cut and paste some info on this to here?

sure, here you go:
Description


Item Specifics

Lapidary Material Type : Tools & Supplies Item Type: diamond abrasives





Up for auction today are several thousand carats of high grade diamond powders divided into 25 carat lots .Pictured above and below are a few thousand carats showing what a small portion of the 300,000 carat surplus looks like. These powders were originally purchased for a large tool making project and have now become surplus. These are the same diamond powders that we have sold on and off for several years so if you purchased from us before you all ready know what you'll be getting . We have a large variety of sizes so you can mix sizes and create a custom 100 carat lot .

NEW(Buy 3 25 carat lots and get the 4th one free 100 total carats)

AVAILIBLE SIZES:

Polish and prepolish size variety are the following mesh : 2500, 4000, 6500, 9000, 14,000 and 60,000

Grinding sizes: 45, 70, 80, 100, 120, 200, and 230

Sanding sizes: 325, 400, 500, 600, 950, and 1300

Notes,

NIckel plated powder is used to create resin bond wheels disc etc. or refurbish worn units. The plating creates a stronger bond between the diamond and the resin extending the life of your tooling.

We carry nickel plated diamond in most of the grinding/sanding sizes.

Bid winners must !!!!must !!!!!must !!!!!!must !!!!!!must !!!!!!and finally must!!!!!!!!!!!!!! contact us after winning to notify us as to what size you need.

The longer you wait to forward that information the later your order will be!!!!!

[ballz0r]

sure, here you go:


thanks mate... what are the bids like? do they have a reserve?

I have no idea how much this stuff is worth

but kayin is right.... screw silver tim... that 60,000 grit would pwn it

[just a noob]

$20.00/vial of the powder i' guessing, not really sure how its sold

[smee]

Lets go plastic block. *clap clap, clap clap clap*

Lets go plastic block. *clap clap, clap clap clap*

Lets go plastic block. *clap clap, clap clap clap*

:D