About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond V
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| Presentation Title |
Non-Equiatomic High-Entropy Refractory Alloys with High Ductility: Hafnium vs. Titanium in Nb-Ta-Based Solutions |
| Author(s) |
Carla Joyce C. Nocheseda, Peter Liaw, Eric Lass |
| On-Site Speaker (Planned) |
Carla Joyce C. Nocheseda |
| Abstract Scope |
The present research uses thermodynamics in ductile R-CCAs exploration, focusing on non-equiatomic alloyed compositions. We demonstrate the feasibility of crafting single-phase solid solutions with exceptional ductility relative to most R-CCAs, using a computational thermodynamic approach, namely the difference in the Gibbs free energy between solid solution phases. Using this concept, non-equiatomic variants can readily be studied across a wide composition space. We illustrate this concept through the introduction of non-equiatomic multi-component HfNbTaTiZr alloys: Hf15Nb40Ta25Ti15Zr5, Hf25Nb40Ta25Ti10Zr5, and Hf10Nb40Ta25Ti25Zr5. This strategy allows us to look at the potency of Hf versus Ti in the base binary BCC Nb-Ta. Despite the reduced configurational entropy, a thorough characterization of these materials evidenced by X-ray Diffraction, uniaxial tensile tests, etc. reveals a striking similarity to extensively studied equiatomic single-phase R-CCAs. This approach broadens the horizon of ductile R-CCAs to encompass non-equiatomic multi-component alloys, allowing customization of stacking fault energy and associated transformation phenomena. |