Multiscale modeling of {theta}{sup '} precipitation in Al-Cu binary alloys

Journal Article · Mon Jun 07 04:00:00 EDT 2004 · Acta Materialia

DOI:https://doi.org/10.1016/j.actamat.2004.03.001· OSTI ID:20634702

Vaithyanathan, V; Wolverton, C; Chen, L Q

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, Journal Name: Acta Materialia Journal Issue: 10 Vol. 52; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ASPECT RATIO
BINARY ALLOY SYSTEMS
CLUSTER EXPANSION
COMPUTERIZED SIMULATION
COPPER ALLOYS
MONTE CARLO METHOD
PRECIPITATION
SOLID SOLUTIONS
STRAINS