Thermophysical properties of zirconium hydride and uranium-zirconium hydride

Thermal diffusivities of ε-phase Zirconium hydrides (ZrH_1.69-2.00) were measured in the temperature range from 300 to 600 K by means of a laser-flash method. The thermal diffusivity of ε-phase Zr hydrides increased with increasing hydrogen concentration and decreased with increasing temperature. The thermal diffusivities of ε-phase ZrH_x with x > 1.83 were larger than that of α-phase Zr. The experimental data on the thermal diffusivity were expressed with the equations as a function of temperature and composition. Moreover, the thermal conductivities of ε-phase Zr hydrides were estimated from the measured data of the thermal diffusivity and the reported data of the density and specific heat. It was found that the ε-phase Zr hydrides were better thermal conductors than α-phase Zr and δ-phase Zr hydrides. The thermal diffusivity and conductivity of U-ZrH_x were also estimated with the ones of ZrH_x and U.