Thermal properties of a reaction hot pressed Mo≤5Si3C≤1 ceramic

Mo≤5Si3C≤1 was produced via reaction hot pressing. X-ray diffraction analysis revealed c-axis crystallographic orientation in the hot pressing direction. The orientation, combined with the inherent thermal expansion anisotropy of the structure, led to preferential microcracking and an overall anisotropic thermal expansion in hot pressed ceramics. Thermal conductivity was calculated for temperatures ranging from −120 to 500 °C from measured heat capacity and thermal diffusivity. Over that range, thermal conductivity increased from ∼9.5 to ∼21.5 W/m K. Electrical resistivity measurements allowed the separation of electrical and phononic contributions and revealed that the thermal conductivity of Mo≤5Si3C≤1 was dominated by electron transport.