Five High Entropy Carbide Ceramics, (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C, (Cr0.2,Hf0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Mo0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Ta0.2,Ti0.2,W0.2,Zr0.2)C, and (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C, Were Synthesized by Carbothermal Reduction of Oxides and Direct Current Sintering. the Five High Entropy Carbide Ceramics Were Determined to Be Nominally Phase-Pure with Relative Densities of More Than 98.9% and Mean Grain Sizes of Less Than 5 Μm. Average Vickers Hardness Values Ranged from 19.2 ± 0.4 GPa for (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C at a Load of 2 Kgf to 43.5 ± 0.4 GPa for (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C at a Load of 0.05 Kgf. Hardness Generally Increased with Increasing the Valence Electron Concentration and Strain as Measured by the Williamson-Hall Analysis. However, Neither Correlation Was Conclusive Enough to Be a Clear Indicator of Hardness. Instead, It Was Determined that a Combination of Effects that Includes the Valence Electron Concentration, Lattice Strain, and Grain Size All Contribute to the Hardness of High Entropy Carbide Ceramics.


Materials Science and Engineering

Publication Status

Open Access


Office of Naval Research, Grant N00014-21-1-2515

International Standard Serial Number (ISSN)

1089-7550; 0021-8979

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2024 American Institute of Physics, All rights reserved.

Publication Date

28 Apr 2024