High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1mm, the samples also had a room-temperature thermal conductivity of 242W⋅(m⋅K)−1and with the temperature increased to 200∘C, the thermal conductivity still maintained at 160W⋅(m⋅K)−1.