Multiscale modeling of θ′ precipitation in Al–Cu binary alloys

Vaithyanathan, V.; Wolverton, Christopher; Chen, Lei

doi:10.1016/j.actamat.2004.03.001

Cited by 271 publications

(136 citation statements)

References 27 publications

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“…A multiscale approach [18] was applied to model Al 2 Cu-θ phase, and was validated by the comparison with the morphology and microstructural experimental data. It was followed by several ab initio studies of Wolverton et al [19][20][21][22][23] and Zhou et al [24]. Wolverton et al [20] and Wang et al [25] showed that copper monolayers were more stable than bilayers.…”

Section: Introductionmentioning

confidence: 99%

DFT Modelling of Cu Segregation in Al-Cu Alloys Covered by an Ultrathin Oxide Film and Possible Links with Passivity

Cornette

Costa

Marcus

2017

Metals

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Abstract:We modelled with Density Functional Theory (DFT) an Al-Cu alloy covered with a passive film, with several Cu concentrations (from the limit of the isolated atom to the monolayer) at the interface with the oxide, as well as Guinier-Preston 1 (GP1) zones. At low (respectively high) concentration, Cu segregates in the first (respectively second) metal layer underneath the passive film. The Cu monolayer is the most stable configuration (−0.37 eV/Cu atom). GP1 zones were modelled, with a three-copper atom cluster in the alloy. The GP1 zone is slightly favoured with respect to the Cu monolayer under the oxide film. A low (respectively high) Cu concentration induces an electronic workfunction increase (respectively decrease) by 0.3 eV (respectively −0.4 to −0.6 eV) as compared to pure Al. In contrast, without oxide, Cu segregation at the Al surface induces no workfunction change at low concentration and an increase of 0.3 eV of the workfunction at high concentration. Thus, the presence of oxide modifies the expected tendency of workfunction increase by adding a more noble metal. For the studied models, no spontaneous electron transfer occurs to the O 2 molecule.

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Section: Introductionmentioning

confidence: 99%

DFT Modelling of Cu Segregation in Al-Cu Alloys Covered by an Ultrathin Oxide Film and Possible Links with Passivity

Cornette

Costa

Marcus

2017

Metals

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“…More generally, such a global approach proves most useful for the determination of interface free energies if (i) the thermodynamically stable directions are not known a priori or if there may be a continuum of stable directions when temperature is sufficiently high and the interfaces roughen or (iii) if the determination of the complete orientation dependence of the interfacial free energy is needed. The latter is especially useful to provide input to continuum-type simulations, such as phase field [22][23][24] or finite element 25 modeling. This paper describes a simple method to determine, from ab initio calculations, the complete orientation-dependence of interface free energies in solid-state crystalline systems.…”

Section: Introductionmentioning

confidence: 99%

Ab initiocalculation of anisotropic interfacial excess free energies

et al. 2014

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We describe a simple method to determine, from ab initio calculations, the complete orientationdependence of interfacial free energies in solid-state crystalline systems. We illustrate the method with an application to precipitates in the Al-Ti alloy system. The method combines the cluster expansion formalism in its most general form (to model the system's energetics) with the inversion of the well-known Wulff construction (to recover interfacial energies from equilibrium precipitate shapes). Although the inverse Wulff construction only provides the relative magnitude of the various interfacial free energies, absolute free energies can be recovered from a calculation of a single, conveniently chosen, planar interface. The method is able to account for essentially all sources of entropy (arising from phonons, bulk point defects, as well as interface roughness) and is thus able to transparently handle both atomically smooth and rough interfaces. The approach expresses the resulting orientation-dependence of the interfacial properties using symmetry-adapted bases for general orientation-dependent quantities. As a by-product, this paper thus provides a simple and general method to generate such basis functions, which prove useful in a variety of other applications, for instance to represent the anisotropy of the so-called constituent strain elastic energy.

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“…More costly simulation techniques such as phase field [16] and kinetic Monte Carlo [17] are also particularly suited to model the morphology of non-spherical precipitates (see the review of Hutchinson on precipitation modelling in Al alloys [18]). …”

Section: Introductionmentioning

confidence: 99%

Coupled precipitation and yield strength modelling for non-isothermal treatments of a 6061 aluminium alloy

et al. 2014

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In age-hardening alloys, high-temperature processes, such as welding, can strongly modify the precipitation state, and thus degrade the associated mechanical properties. The aim of this paper is to present a coupled approach able to describe precipitation and associated yield stresses for non-isothermal treatments of a 6061 aluminium alloy. The precipitation state (in terms of volume fraction and precipitate size distribution) is modelled thanks to a recent implementation of the classical nucleation and growth theories for needle-shaped precipitates. The precipitation model is validated through small-angle neutron scattering and transmission electron microscopy experiments. The precipitation size distribution is then used as an entry parameter of a micromechanical model for the yield strength of the alloy. Predicted yield stresses are compared to tensile tests performed with various heating conditions, representative of the heat-affected zone of a welded joint.

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Multiscale modeling of θ′ precipitation in Al–Cu binary alloys

Cited by 271 publications

References 27 publications

DFT Modelling of Cu Segregation in Al-Cu Alloys Covered by an Ultrathin Oxide Film and Possible Links with Passivity

DFT Modelling of Cu Segregation in Al-Cu Alloys Covered by an Ultrathin Oxide Film and Possible Links with Passivity

Ab initiocalculation of anisotropic interfacial excess free energies

Coupled precipitation and yield strength modelling for non-isothermal treatments of a 6061 aluminium alloy

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