Will high-entropy carbides and borides be enabling materials for extreme environments?

The concept of multi-principal component has created promising opportunities for the development of novel high-entropy ceramics for extreme environments encountered in advanced turbine engines, nuclear reactors, and hypersonic vehicles, as it expands the compositional space of ceramic materials with tailored properties within a single-phase solid solution. The unique physical properties of some high-entropy carbides and borides, such as higher hardness, high-temperature strength, lower thermal conductivity, and improved irradiation resistance than the constitute ceramics, have been observed. These promising properties may be attributed to the compositional complexity, atomic-level disorder, lattice distortion, and other fundamental processes related to defect formation and phonon scattering. This manuscript serves as a critical review of the recent progress in high-entropy carbides and borides, focusing on synthesis and evaluations of their performance in extreme high-temperature, irradiation, and gaseous environments.

Automated summary

The concept of multi-principal component has opened up opportunities for novel high-entropy ceramics in extreme environments. The unique physical properties of high-entropy carbides and borides, such as higher hardness and improved irradiation resistance, can be attributed to compositional complexity and lattice distortion. This review focuses on the synthesis and performance evaluation of high-entropy carbides and borides in extreme high-temperature, irradiation, and gaseous environments.