Thermal and Mechanical Properties of Refractory High‐Entropy Alloy Composites with TiC in Nonequal Molar CrMoNbTaTiZr at Elevated Temperatures

The composite materials incorporating titanium carbide with nonequal molar CrMoNbTaTiZr refractory high‐entropy alloys are synthesized through powder metallurgy using a reactive sintering technique. This research examines the effect of temperature on the mechanisms of sintering by evaluating the formability and microstructure. The optimal sintering temperature of 1600 °C yields the highest reactivity and densification, achieving a density of 5.74 g cm − 3 , which is ≈29.79% lower than that of the monolithic alloy, thereby demonstrating its potential for applications. Furthermore, thermal analyses are conducted to assess the heat capacity, thermal conductivity, and thermal expansion from ambient temperature to 1200 °C, revealing that the composite possesses a low coefficient of thermal expansion. The reactive sintering mechanism, particularly the degree of TiC formation, significantly affects thermal conductivity; below 600 °C, density and porosity are the primary factors, while at elevated temperatures, the increased heat capacity due to phase evolution becomes more pronounced. High‐temperature hardness indicates remarkable performance, with a hardness of 405 HV at 1000 °C and a low softening coefficient. This study highlights the efficacy of reactive sintering in the development of refractory high‐entropy alloy‐based composites that possess low density and superior thermal and mechanical properties.