Ti-V alloy phase diagram: DFT-based cluster approach
ORAL
Abstract
V is an important alloying element for Ti since it stabilizes the high-temperature bcc phase of Ti at lower temperatures, while minimizing the formation of intermetallic compounds [1]. Theoretical determination of the Ti-V phase diagram must take into account structures based on both bcc and hcp lattices over the full V concentration range. With the cluster expansion formalism for alloys [2], DFT calculations determine the energies of all structures necessary for constructing the cluster expansion for the energetics of the alloy. Preliminary results indicate the DFT-based cluster approach determines solubility limits and transformation temperatures that are in good agreement with the experimental phase diagram [3]. \newline [1] M. J. Donachie, Jr., \textit{Titanium: A Technical Guide}. ASM International: Metals Park, OH (1988). [2] D. de Fontaine, Solid State Phys. \textbf{47}, 33 (1994). [3] T. B. Massalski, et al., \textit{Binary Alloy Phase Diagrams}, Vol. 2. ASM International: Metals Park, OH (1986).
*Supported in part by the DOE. We thank R. G. Hennig of Cornell U. for useful discussions.
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