About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
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Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond V
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Presentation Title |
Study of Ductility and Plasticity of HfTiZrNbTa High-Entropy Alloys Using In-Situ Neutron Diffraction |
Author(s) |
Lia Amalia, John Whitlow, Xuesong Fan, Nathan Grain, Melanie Moczadlo, Eric Lass, Yanfei Gao, Ke An, Yan Chen, Dunji Yu, Peter Liaw |
On-Site Speaker (Planned) |
Lia Amalia |
Abstract Scope |
Superalloys are currently used up to 1,000oC although they are limited by the solvus and melting temperatures. Refractory high-entropy alloys (RHEAs) have shown promising high-temperature properties compared to other classes of high-entropy alloys (HEAs). However, they are brittle at room temperature, hindering further mechanical processing. It is also reported that RHEAs are difficult to cast in large dimensions due to fast cooling rate. In this study, we fabricated compression and tension samples with seven different compositions derived from HfNbTaTiZr, predicted using calculation of phase diagrams (CALPHAD), by calculating the phase transformation Gibbs free energy from the body-centered-cubic to hexagonal-close-packed structure. An in-situ neutron-diffraction study was conducted, then single peak and full pattern analyses were performed using the VULCAN data reduction and interactive visualization software. All seven compositions showed compression plasticity and four of them showed tension ductility, while one of them exhibited transformation-induced plasticity behavior. |