About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
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Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond II
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Presentation Title |
Deformation Behavior in the Refractory High-entropy Alloys |
Author(s) |
Chanho Lee, George Kim, Yi Chou, Michael C Gao, Ke An, Gian Song, Yi-Chia Chou, Wei Chen, Saryu J Fensin, Peter K Liaw |
On-Site Speaker (Planned) |
Chanho Lee |
Abstract Scope |
Single-phase solid-solution refractory high-entropy-alloys (HEAs) show remarkable mechanical properties, such as high yield strength with significant softening resistance at elevated temperatures. Hence, the in-depth study of the deformation behavior for body-centered-cubic (BCC) refractory HEAs is a critical issue to explore the uncovered/unique deformation mechanisms. We have investigated the elastic- and plastic-deformation behaviors of a single BCC NbTaTiV refractory HEA at elevated temperatures, using integrated experimental efforts and theoretical calculations. The in-situ neutron-diffraction results reveal a transition of the elastic-deformation feature from isotropic to anisotropic modes at elevated temperatures. The single-crystal elastic-moduli and macroscopic Young’s, shear and bulk moduli were determined from the in-situ neutron diffraction, showing the great agreement with first-principles calculations, machine-learning, and resonant-ultrasound spectroscopy results. Furthermore, the edge-dislocation-dominant plastic-deformation behaviors, which are different from conventional BCC alloys, have been quantitatively described by the Williamson-Hall plot profile modeling, which is further experimentally verified by the high-angle-annular-dark-field (HAADF) scanning-transmission-electron-microscopy (STEM). |