Electrically and thermally conductive SiC ceramics

Abstract

Electrically and thermally conductive SiC ceramics were fabricated by hot-pressing β-SiC, 2 or 4 vol% TiN, and 2 vol% Y2O3 powder mixtures in a nitrogen atmosphere. X-ray diffraction data indicated that the specimens consisted mostly of β-SiC grains and traces of α-SiC and Ti2CN clusters. Highly-conductive Ti2CN clusters segregated between SiC grains contributed to reduce the electrical resistivity of the TiN-doped SiC specimens. The high thermal conductivity of the TiN-doped SiC specimens was attributed to the lack of solubility of Ti and Y in the SiC lattice and the suppression of a massive β→α phase transformation in SiC. The electrical resistivity and thermal conductivity of the SiC with 2 vol% TiN specimen were 2.4 × 10-3Ω·cm and 174.1 W/m·K, respectively.