Effects of Zr addition on lattice strains and electronic structures of NbTaTiV high-entropy alloy
Autor: | Lizhi Ouyang, Michael C. Gao, Ke An, Saryu Fensin, Peter K. Liaw, Gian Song, Chanho Lee |
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Rok vydání: | 2022 |
Předmět: |
Materials science
Condensed matter physics Mechanical Engineering Neutron diffraction Fermi level Condensed Matter Physics Stress (mechanics) Condensed Matter::Materials Science symbols.namesake Brittleness Mechanics of Materials symbols General Materials Science Density functional theory Deformation (engineering) Ductility Stress concentration |
Zdroj: | Materials Science and Engineering: A. 831:142293 |
ISSN: | 0921-5093 |
Popis: | The room-temperature (RT) deformation behavior for two single-phase body-centered-cubic (BCC) refractory high-entropy alloys (RHEAs), NbTaTiV and NbTaTiVZr, has been comprehensively investigated via in-situ neutron-diffraction experiments. Our work shows that the addition of Zr leads to the transition of mechanical response from ductile to brittle behavior. The results of lattice-strain evolutions obtained from in-situ neutron diffraction for the ductile NbTaTiV RHEA exhibit atypical plastic-deformation behavior, i.e., the reduced plastic-anisotropic deformation, leading to an even distribution of the applied stress amongst the grains with different orientations rather than forming stress concentrations in {200}-oriented grains during plastic-deformation. Density functional theory (DFT) analysis shows that NbTaTiVZr has a lower electron density at the Fermi level, larger lattice distortion, and stronger charge transfer, as compared to NbTaTiV, suggesting higher strength and lower ductility in NbTaTiVZr, which are consistent with the current experimental results. |
Databáze: | OpenAIRE |
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