| Abstract Scope |
High-entropy ceramics (HECs), including high-entropy carbides and carbonitrides (HEC/HECNs), are promising candidates for structural applications in extreme environments due to their remarkable thermal stability, chemical inertness, and mechanical robustness. Traditional materials often degrade at higher temperatures (>1200°C) through phase instability or mechanical softening. Several compositions of HECs and HECNs offer favorable alternatives due to entropy stabilized structures retaining their hardness under extreme conditions.
Ideal HEC/HECN systems form single-phase solid solutions which can undergo spinodal decomposition when under thermal treatment. This decomposition can result in nanoscale compositional barriers hindering dislocation motion and enhancing hardness. The inherent compositional flexibility of HEC/HECNs enables the fine-tuning of physical and chemical properties to meet specific performance criteria. By systematically varying elemental constituents, it is possible to design materials with targeted thermal, chemical, and mechanical behaviors, surpassing the performance of conventional ceramics and metals in similar conditions. |