Measurement of ZrC properties up to 5000 K by fast electrical pulse heating method

Sintered zirconium carbide (C/Zr ≈ 0.95) was studied by pulsed electrical heating method with microsecond duration. Thermophysical properties such as Joule energy, heat of melting, the specific heat, and electrical resistance were measured in the temperature range of 2500–5000 K by this method for the first time. The steep increase of the specific heat just before melting may be associated with the formation of nonequilibrium pairs point Frenkel defects at high temperatures under fast heating. It was established that the melting of the carbide occurs in the temperature range: solidus—3450 K and liquidus—3850 K, that is close to the values presented in some equilibrium phase diagrams of the system Zr–C. This means that there is no shift of the phase transition points at the heating rates up to 108 K/s, and makes it possible to use this method for the study of high temperature behavior of the complex substances. The comparison of the data of measured properties with the literature data is provided.