Thermal properties of La2O3-doped ZrB2- and HfB2-based ultra-high temperature ceramics

Thermal properties of La2O3-doped ZrB2- and HfB2-based ultra high temperature ceramics (UHTCs) have been measured at temperatures from room temperature to 2000 °C and compared with SiC-doped ZrB2- and HfB2-based UHTCs and monolithic ZrB2 and HfB2. Thermal conductivities of La2O3-doped UHTCs remain constant around 55-60 W/mK from 1500 °C to 1900 °C while SiC-doped UHTCs showed a trend to decreasing values over this range.