Improved Thermal Diffusivity Method Applied to TiB2, ZrB2, and HfB2 from 200°–1300°C

The thermal diffusivities of dense polycrystalline TiB2, ZrB2, and HfB2 were measured by a laser flash method over the temperature range 200°–1300°C. An investigation of the effects of radial heat flow was performed and a special sample shape was used to comply with the assumption of one-dimensional heat flow. The values of the diffusivities were found to be described by the empirical equations αTiB2=0.1290+[39.26/T(∘K)]cm2/secαZrB2=0.1424+[81.17/T(∘K)]αHfB2=0.1436+[35.97/T(∘K)].Values of thermal conductivity computed from the diffusivity data were found to be described by λTiB2=0.7867+[10.30/T(∘K)]W/cm degλZrB2=0.8235+[108.2/T(∘K)]λHfB2=0.7157+[34.24/T(∘K)].