Effect of Sintering Temperature on the Properties of Highly Electrical Resistive SiC Ceramics as a Function of Y(2)O(3)-Er(2)O(3) Additions

Silicon carbide (SiC) ceramics with Y(2)O(3)-Er(2)O(3) as sintering additives were prepared by spark plasma sintering (SPS). The effects of sintering temperatures and Y(2)O(3)-Er(2)O(3) contents on the microstructure, thermal conductivity, electrical, and mechanical properties were investigated. The increasing of sintering temperatures promoted the densification of SiC ceramics, thus increasing the thermal conductivity and electrical resistivity. With the increase of the sintering additive contents, the electrical resistivity increased due to the formation of the electrical insulating network; and the thermal conductivity first increased and then decreased, which was related to the content and distribution of the secondary phase among the SiC grains. The SiC ceramics sintered at 2000 °C with 9 wt.% Y(2)O(3)-Er(2)O(3) exhibited higher electrical resistivity and thermal conductivity, which were 4.28 × 10(9) Ω·cm and 96.68 W/m·K, respectively.