Thermal and electrical properties of spark plasma sintered (Ti,Cr)B2 ceramics

Abstract

AbstractThermal and electrical properties were measured for TiB2 ceramics containing varying CrB2 contents up to 33 mol%. The room‐temperature thermal diffusivity decreased with increasing Cr content from 0.330 ± 0.003 cm2/s for pure TiB2 to 0.060 ± 0.003 cm2/s for (Ti0.66Cr0.33)B2. The amount of anisotropy in the coefficients of thermal expansion increased with increasing Cr content and the c‐axis had the greatest dependence on Cr addition, with an increase of more than 25% in the thermal expansion for 33 mol% CrB2 compared to TiB2, whereas the a‐axis only increased by about 8%. The electrical conductivity was the lowest for (Ti0.66Cr0.33)B2 at ∼8.5 × 103 S/cm compared to ∼106.1 × 103 S/cm for nominally pure TiB2. Overall, the addition of CrB2 as a sintering aid for TiB2 was shown to have a significant effect on the thermal and electrical properties of TiB2 for additions as small as 5 mol% CrB2.