The effect of porosity on the thermal conductivity of Al-12 wt.% Si/SiC composites

The effect of porosity (up to 13%) on the thermal conductivity of composites obtained by infiltration of Al-12 wt.% Si alloy into SiC particulate preforms has been determined. The thermal conductivity of these composites gradually increases with the applied infiltration pressure given the inherent reduction in porosity. A simple application of the Hassel man-Johnson model in a two-step procedure (which accounts for the presence of both SiC particles and voids randomly dispersed in a metallic matrix) offers a good approximation of the experimental results. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.