Multiscale modeling of {theta}{sup '} precipitation in Al-Cu binary alloys
We present a multiscale model for studying the growth and coarsening of {theta}' precipitates in Al-Cu alloys. Our approach utilizes a novel combination of the mesoscale phase-field method with atomistic approaches such as first-principles total energy and linear response calculations, as well as a mixed-space cluster expansion coupled with Monte Carlo simulations. We give quantitative first-principles predictions of: (i) bulk energetics of the Al-Cu solid solution and {theta}{sup '} precipitate phases, (ii) interfacial energies of the coherent and semi-coherent {theta}{sup '}/Al interfaces, and (iii) stress-free misfit strains and coherency strain energies of the {theta}{sup '}/Al system. These first-principles data comprise all the necessary energetic information to construct our phase-field model of microstructural evolution. Using our multiscale approach, we elucidate the effects of various energetic contributions on the equilibrium shape of {theta}{sup '} precipitates, finding that both the elastic energy and interfacial energy anisotropy contributions play critical roles in determining the aspect ratio of {theta}{sup '} precipitates. Additionally, we have performed a quantitative study of the morphology of two-dimensional multi-precipitate microstructures during growth and coarsening, and compared the calculated results with experimentally observed morphologies. Our multiscale first-principles/phase-field method is completely general and should therefore be applicable to a wide variety of problems in microstructural evolution.
- OSTI ID:
- 20634702
- Journal Information:
- Acta Materialia, Vol. 52, Issue 10; Other Information: DOI: 10.1016/j.actamat.2004.03.001; PII: S135964540400134X; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 1359-6454
- Country of Publication:
- United States
- Language:
- English
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