SiC-B4C composites for synergistic enhancement of thermoelectric property

SiC-B4C composites were fabricated by hot pressing of beta-SiC and B4C powder mixture. The Seebeck coefficient was determined at 300-900 degreesC in air. The SiC-B4C composites exhibited very high value. Especially, the Seebeck coefficient of SiC-30wt.%B4C composite was about 700 mu/K at 900 C. Such a high Seebeck coefficient is very attractive. Monolithic SiC and B4C had the Seebeck coefficient of 100-400 muV/K, respectively. In SiC-B4C composite system, the Seebeck coefficient had been increased by the combination of SiC and B4C. In TEM observation, many stacking faults were observed in SiC-B4C composites. The presence of stacking faults may be one reason for the high Seebeck coefficient of SiC-B4C composite. (C) 2003 Elsevier Ltd. All rights reserved.