Maxtal Graphite Heatsink Material - 450w/m·k: Maxtal Carbon Tech Co. Ltd. produce highly thermally conductive Graphite for a variety of uses, with conductivity reaching as high as 450W/m-K in the X-X,Y-Y axis. "High thermal conductivity graphite is a new conductivity and heat sinks material which has the high thermal conductivity, big specific heat capacity, good heat stability, small coefficient thermal expansion and corrosion resistant, etc. The material itself has the strong air sink characteristics (cross-ventilation ability)."

Carbon nanofibre forest cuts thermal resistance: NASA is using carbon nanotubes to cut thermal resistance, aiming to improve heat flow between chips and heatsinks. Li’s alternative uses a form of nanotube called carbon nanofibres in the interface. With two [plain] pieces of silicon, the interface resistance is about 2cm²K/W which can be improved with grease or solder. People are shooting for less than 0.5cm²K/W; and 0.2 for the next generation. We can achieve 0.2 already and it is under-optimised.” The NASA interface relies on the incredible thermal conductivity of carbon nanotubes. “There is a lot of interest in this thermal conductivity. There is literature to say it is as high as diamond. But it is highly anisotropic,” said Li. Along the length of the tube it has diamond-like thermal conductivity, but heat does not pass into the side of the tube easily. “If nanotubes are packed together like spaghetti, thermal conductivity is very poor.

IG-430 Graphite-Copper Heatsink Research: In this PDF by W.Y. Maeng from the Korean Atomic Energy Research Institute, the author discusses a novel heatsink fabricated from graphite brazed to a copper baseplate for a proton accelerator. The one step brazing process for the joining of Cu-graphite plate uses TiCuSil alloy. There is some interesting cooling technology being discussed here, but keep in mind that while Graphite has a relatively good thermal conductivity it is generally only in one plane). This research note goes on to test IG-430 graphite impregnated with Cu and Ag alloys. "The graphite used for front facing material is IG-430 of Toyo Tanso. The copper plate for the cooling jacket material is made with OHFC (Oxygen Free High Conductivity Copper, ASTM B170 Grade 1). The filler material for the brazing is TiCuSil alloy (4.5%Ti-27.7%Cu-68.8%Ag, Wesgo Metals)."

Nanotubes act as 'thermal Velcro' to reduce computer-chip heating: "Engineers have created carpets made of tiny cylinders called carbon nanotubes to enhance the flow of heat at a critical point where computer chips connect to cooling devices called heat sinks, promising to help keep future chips from overheating. Researchers are trying to develop new types of "thermal interface materials" that conduct heat more efficiently than conventional materials, improving overall performance and helping to meet cooling needs of future chips that will produce more heat than current microprocessors. The materials, which are sandwiched between silicon chips and the metal heat sinks, fill gaps and irregularities between the chip and metal surfaces to enhance heat flow between the two. Purdue University researchers have made several new thermal interface materials with carbon nanotubes, including a Velcro-like nanocarpet. Recent findings have shown that the nanotube-based interfaces can conduct several times more heat than conventional thermal interface materials at the same temperatures. The nanocarpet, called a "carbon nanotube array thermal interface," can be attached to both the chip and heat sink surfaces."

Super Carbon Foam Heat Exchangers: Copper is so last year, the new material du jour is Super Carbon Foam. Here are a couple examples of carbon foam heat exchangers from the company CFoam. "There has been significant research activity on developing carbon foam heat exchangers primarily because of their potential weight savings and high efficiency. Carbon foam heat exchangers are predicted to weigh 50% less than conventional high-temperature, metallic core pre-cooler/heat exchanger designs, and are also expected to have twice the efficiency of traditional heat exchangers. CFOAM, because of its high structural strength, is a viable material for use on helicopters, aircraft and ships. CFOAM’s significantly higher strength allows greater flexibility in the heat exchanger fin and core designs which cannot be obtained with the weaker pitch-based products."