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First-principles study,fabrication, and characterization of (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)C high-entropy ceramic |
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| Authors: | Beilin Ye Tongqi Wen Kehan Huang Cai-Zhuang Wang Yanhui Chu |
| Affiliation: | 1. School of Materials Science and Engineering, South China University of Technology, Guangzhou, China;2. MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Natural and Applied Sciences, Northwestern Polytechnical University, Xi'an, China Ames Laboratory-USDOE, Iowa State University, Ames, Iowa;3. Ames Laboratory-USDOE, Iowa State University, Ames, Iowa Department of Physics and Astronomy, Iowa State University, Ames, Iowa |
| Abstract: | The formation possibility of (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)C high-entropy ceramic (HHC-1) was first analyzed by the first-principles calculations, and then, it was successfully fabricated by hot-pressing sintering technique at 2073 K under a pressure of 30 MPa. The first-principles calculation results showed that the mixing enthalpy and mixing entropy of HHC-1 were −0.869 ± 0.290 kJ/mol and 0.805R, respectively. The experimental results showed that the as-prepared HHC-1 not only had an interesting single rock-salt crystal structure of metal carbides but also possessed high compositional uniformity from nanoscale to microscale. By taking advantage of these unique features, it exhibited extremely high nanohardness of 40.6 ± 0.6 GPa and elastic modulus in the range from 514 ± 10 to 522 ± 10 GPa and relatively high electrical resistivity of 91 ± 1.3 μΩ·cm, which could be due to the presence of solid solution effects. |
| Keywords: | electrical resistivity first-principles calculations high-entropy ceramics mechanical properties metal carbides |