The influence of Si distribution and content on the thermoelectric properties of SiC foam ceramics

SiC foam ceramics were prepared by macromolecule pyrogenation combined with reaction bonding methods. The thermoelectric properties of SiC foams with different strut layer structures (formed by different Si distribution) containing 8% and 15% Si have been measured from room temperature up to 873 K. The results show that the electrical resistivity of SiC foam ceramics varies evidently with the strut layer structures and Si content. Also, there is a strong influence of the strut layer structures oil Seebeck coefficients for SiC foam ceramics. SiC foam with a three-layer strut structure exhibits the highest value of the power factor, which leads to an improvement of the thermoelectric properties of SiC foam ceramics. (C) 2007 Elsevier Inc. All rights reserved.