Thermal Conductivity of ZrB 2 SiCB 4 C from 25 to 2000 °C

The thermal diffusivities of ZrB 2 –SiC (10.7, 21.9, or 48.7 vol% SiC) with B 4 C sintering aid were measured over 25–2000 °C using laser flash. The composition with the highest SiC showed the highest thermal conductivity ( k ) at 25 °C, but the lowest above ≈400 °C, because of the greater k temperature sensitivity of the SiC phase. Finite difference calculations of k , using selected literature data for the individual phases, and the concentration of phases from microstructures, correctly predicted temperature and phase concentration dependencies, but were lower than experimental results. The k of pure ZrB 2 and SiC as a function of temperature were back‐calculated from the experimental results for the multi‐phase materials; they were in good agreement with specific literature values.