# A micromechanics-based model for shear-coupled grain boundary migration in bicrystals

Abstract : A complete micromechanics-based model is here proposed using the concepts of continuum kinematics and thermodynamics. A new constitutive framework is proposed to describe stress-induced shear-coupled'' grain boundary (GB) migration. Like non diffusive phase-transformations, shear-coupled GB migration can be considered on the thermodynamics point of view of conservative nature until high temperature with respect to melting point (i.e., diffusionless but thermally activated). The micromechanics-based continuum model can include intra-crystalline slip, GB sliding and shear-coupled GB migration as additive dissipative mechanisms. To illustrate the present theory, the model is applied to shear-coupled GB migration in the case of three flat'' Cu bi-crystals [001] with symmetric tilt GB (STGB): Sigma 17(410) (theta = 28.07 degrees), Sigma 5(210) (theta = 53.13 degrees), Sigma 41(540) (theta = 77.32 degrees). Molecular dynamics (MD) simulations under simple shear loading are first performed to identify the active shear coupling modes, the stick-slip behavior at 0 K and 500 K and the bicrystal finite size dependence on the shear stress responses. The results of the micromechanical model are discussed in comparison with MD simulations. The effects of anisotropic vs. isotropic elastic properties on effective elastic shear Moduli, overall shear stress drop magnitudes and dissipated energy during GB migration are analyzed for these STGB.
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Article dans une revue
International Journal of Plasticity, Elsevier, 2013, 44, pp.68-94. 〈10.1016/j.ijplas.2012.11.011〉
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https://hal.univ-lorraine.fr/hal-01500654
Contributeur : Lem3 Ul <>
Soumis le : lundi 3 avril 2017 - 15:23:13
Dernière modification le : mercredi 12 septembre 2018 - 01:27:10

### Citation

Stéphane Berbenni, Bhasker Paliwal, Mohammed Cherkaoui. A micromechanics-based model for shear-coupled grain boundary migration in bicrystals. International Journal of Plasticity, Elsevier, 2013, 44, pp.68-94. 〈10.1016/j.ijplas.2012.11.011〉. 〈hal-01500654〉

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