Thermal conductivity greases

Ecrotherm . (Emerson ft Cuming] Silicone or epoxy compds. thermally conductive greases, adhesives, coatings, enctpsulants. 

Wells, R.H. and Hunadi, R., Low outgassing, high thermal conductivity greases, in International Conference on Microelectronics, 1998. 

Corning high-vacuum silicone grease on Gas-Chrom 175°, with thermal conductivity detection and He as carrier gas. above. ... 

Table 19.5 shows the characterization of the four nanocomposites (greases). The thermal conductivity seems saturated and stays around 0.25-0.27 W mK . Compared to the values of 0.17-0.18 W mK for the base polymeric oils (polyalphaolefin and/or polyol ester), the effective thermal conductivities of the nanocomposites (nanogreases) have increased by about 60-70%. Also, it is possible to theoretically predict the effective thermal conductivity ke of greases using the Fricke equation (Equation 19.2) or the... 

The calculated TC is also listed in Table 19.5. The less than calculated thermal conductivity value demonstrates the existence of thermal contact resistance and lack of efficient nanotube-nanotube physical contacts in the greases [34,35]. 

Thermal conductivities of grease, water, and water/grease... 

Figure 19.15 Thermal conductivity vs. time for nanocomposite (grease) with W wt% SWNT and different Fe203 loading concentrations under a magnetic field (0.62 kG) (A) 0 wt% (B) 5 wt% (C) 10 wt% and (D) 20 wt%. (Reproduced with kind permission from NLGI. Copyright...

Even after being exposed to a magnetic field (1.46 kG) for more than 72 hours, there was no apparent TC change in the sample. The combined results for all of the thermal conductivity measurements of the grease containing the Ni-coated carbon nanotubes can be found in Table 19.11. 

Although there are many unknown or uncertain factors related to the fundamental nature of nanocomposites (nanotube greases), the increased electrical and thermal conductivities by addition of nanofillers strongly indicate that these nanotube greases could replace the current commercial greases (lithium, calcium, aluminum, and polyurea) and have a promising future in commercial applications. 

AN EXPERIMENTAL DETERMINATION OF THE THERMAL CONDUCTIVITY OF SOAP CONCENTRATES, GREASE AND VISCOUS LIQUIDS. M.S. THESIS. 

THERMAL CONDUCTIVITY OF APIEZON N GREASE AT LIQUID HELIUM TEMPERATURES. 

Thermal grease uses a hydrocarbon oil or silicone as a base and is filled with a thermally conductive material such as aluminum oxide or zinc oxide. The typical thermal grease used in production applications has a thermal conductivity of approximately 1.0 W/m K. The typical thickness is 0.001-0.003 in. Newer thermal greases have thermal conductivities as high as 16 W/m K [15,24]. 

Mica insulators, having a thickness of 0.002-0.003 in., have been used for many years in mounting power devices to heat sinks. Used in conjunction with thermal grease, they provide a low-cost method of reducing the thermal resistance caused by air gaps. Mica has a thermal conductivity of 0.75 W/m K [9]. 

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