Ghosh, Gautam and van de Walle, Axel and Asta, Mark (2007) First-Principles Phase Stability Calculations of Pseudobinary Alloys of (Al,Zn)3Ti with L12, D022, and D023 Structures. Journal of Phase Equilibria and Diffusion, 28 (1). pp. 9-22. ISSN 1547-7037 http://resolver.caltech.edu/CaltechAUTHORS:GHOjped07
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The thermodynamic and mechanical stability of intermetallic phases in the Al3Ti-Zn3Ti pseudobinary alloy system is investigated from first-principles total energy calculations through electronic density-functional theory within the generalized gradient approximation. Both supercell calculations and sublattice-cluster-expansion methods are used to demonstrate that the addition of Zn to the Al sublattice of Al3Ti stabilizes the cubic L12 structure relative to the tetragonal D022 and D023 structures. This trend can be understood in terms of a simple rigid-band picture in which the addition of Zn modifies the effective number of valence electrons that populate bonding and anti-bonding states. The calculated zero-temperature elastic constants show that the binary end members are mechanically stable in all three ordered phases. These results point to a promising way to cost effectively achieve the stabilization of L12 precipitates in order to favor the formation of a microstructure associated with desirable mechanical properties.
|Additional Information:||Author preprint. Published version, Copyright © 2007 ASM International. Received: 24 October 2006. Published online: 19 April 2007. This research was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract Nos. DE-FG02-02ER45997 (GG) and DOE-FG02-01ER45910 (AvdW and MA). Supercomputing resources were provided by the National Partnership on Advanced Computational Infrastructure (NPACI) at the University of Michigan at Ann Arbor and at the University of Illinois at Urbana-Champaign.|
|Subject Keywords:||cluster expansion, computational studies, crystal structure, elastic properties, electronic structure, first principles, intermetallics|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Archive Administrator|
|Deposited On:||03 Sep 2007|
|Last Modified:||26 Dec 2012 09:41|
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