Abstract

High-entropy carbides (HECs) are often treated as a single material class defined by configurational entropy; however, their properties are governed by composition-specific defects and grain-boundary chemistry. This study demonstrates that substituting a single element can qualitatively change grain-boundary structure and fracture behavior in HEC ceramics. Two HECs, (Cr,Hf,Ta,Ti,Zr)C (HEC-Cr) and (Hf,Ta,Ti,W,Zr)C (HEC-W), were examined via electron microscopy, atom probe tomography, and molecular dynamics simulations. Simulations predict preferential segregation of Cr, W, and Zr to grain boundaries. Experiments confirmed Cr enrichment at grain boundaries and the formation of W-rich nanograins along boundary networks. Mechanical testing revealed that these compositional differences translated into grain-boundary cohesion differences: HEC-Cr exhibited intergranular fracture and lower compressive strength (2.66 GPa), whereas HEC-W exhibited trans granular fracture and higher strength (5.95 GPa). These findings establish grain-boundary segregation as a dominant mechanism linking composition to mechanical performance in HECs and underscore the advantages of integrated chemistry-microstructure design strategies rather than thermodynamics alone.

Department(s)

Materials Science and Engineering

Publication Status

Open Access

Keywords and Phrases

fracture behavior; grain boundaries; high-entropy carbides; high-entropy ceramics; mechanical behavior

International Standard Serial Number (ISSN)

1551-2916; 0002-7820

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Wiley, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 May 2026

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