The temperature dependence of effective thermal conductivity of open-celled steel alloy foams
Zhao, C. Y., Lu, T. J., Hodson, H. P. and Jackson, J. D.
2004 Materials Science and Engineering: A, 367(1?): 123-131
Cellular metal foams; Thermal conductivity; Thermal radiation; Natural convection
Zhao, C. Y., Lu, T. J., Hodson, H. P. and Jackson, J. D., (2004), "The temperature dependence of effective thermal conductivity of open-celled steel alloy foams", Materials Science and Engineering: A, 367(1?): 123-131.
Abstract:
The effective thermal conductivity of steel alloy FeCrAlY (Fe¡ª20 wt.% Cr¡ª5 wt.% Al¡ª2 wt.% Y¡ª20 wt.%) foams with a range of pore sizes and porosities was measured between 300 and 800 K, under both vacuum and atmospheric conditions. The results show that the effective thermal conductivity increases rapidly as temperature is increased, particularly in the higher temperature range (500¨C800 K) where the transport of heat is dominated by thermal radiation. The effective conductivity at temperature 800 K can be three times higher than that at room temperature (300 K). Results obtained under vacuum conditions reveal that the effective conductivity increases with increasing pore size or decreasing porosity. The contribution of natural convection to heat conduction was found to be significant, with the effective thermal conductivity at ambient pressure twice the value of vacuum condition. The results also show that natural convection in metal foams is strongly dependent upon porosity.
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