Thermoelectric properties of SiB6-C composites

In this study, SiB6-0 similar to 20wt%C composites were investigated relationship between microstructure and electrical conductivity prepared by hot pressing. The samples were sintered at 1973 K for 3.6 ks in vacuum under a pressure of 25 MPa. The relative density of sintered body was measured by Archimedes' method. The relative density of SiB6-0, 5, 10, 15 and 20wt%C composites were 99.6%, 98.5%, 98%, 96.5% and 75%, respectivity. SiB6-0 similar to 20wt%C composites were cut out for the electrical conductivity and Seebeck coefficient. The high temperature electrical conductivity was measured using a D.C. four-terminal method in tube type electric furnace at 373 to 1073 K, in Ar-5%H-2 gas atmosphere. The Seebeck coefficient was measured at 373 to 1073 K. As a result of measuring, maximum point of electrical conductivity of SiB6-10wt%C was 1.61 x 10(3) S/m. The electrical conductivity of SiB6-C composite was higher than SiB6 sintered body. The microstructure of SIB,0 similar to 20wt%C composite observed by scanning electron microscope (SEM) and electron prove X-ray micro analyzer (EPMA). The composition of SiB6-C composites were changed to B4C and SiC. However, SiB6 was remain in SiB6-C composites.