High-Entropy Carbide Ceramics

GB-Strengthened Superhard

Atomic volume mismatch drives grain boundary segregation to enhance cohesion, with multi-objective optimization yielding superhard compositional domains.

Yalin, Li · Sirui, Xu · Zhao, Shijun · Zhang, Kan · Wu, Zhenggang

Journal of Materials Science and Technology 2027

Specifications

Segregation energy-volume difference linear correlation coefficient

{'zh': '0.9', 'en': '0.9'}

Advantages

Grain boundary cohesion enhanced

Elemental segregation arising from chemical disorder in multicomponent transition metal carbides significantly enhances grain boundary cohesion, effectively mitigating mechanical degradation.

Clear design rule

Segregation energy correlates approximately linearly with atomic volume difference, with smaller-volume elements segregating more strongly, enabling straightforward composition screening.

Co-segregation predictable

A co-segregation model accurately quantifies elemental concentrations at grain boundaries, overcoming the challenge of predicting segregation in multicomponent systems.

Rapid discovery of superhard compositions

Multi-objective optimization enables rapid exploration of compositional spaces, with an experimentally validated superhard domain, significantly shortening the material development cycle.

Applications

• Ultrahigh-Temperature Ceramics：As UHTC matrix, utilizes grain boundary strengthening to suppress intergranular fracture, enhancing high-temperature structural reliability.
• Thermal Protection Materials：For thermal protection components, composition design yields superhard high-entropy carbides resisting extreme thermo-mechanical environments.
• High-Entropy Ceramics：In multicomponent carbides, volume mismatch drives segregation, establishing a new strengthening mechanism for high-entropy ceramics.