Phase field modeling of a glide dislocation transmission across a coherent sliding interface

Zheng, Songlin; Ni, Yong; He, Linghui

doi:10.1088/0965-0393/23/3/035002

Cited by 11 publications

(4 citation statements)

References 48 publications

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“…The elastic moduli are: C 11 =168.4GPa, C 12 =121.4GPa and C 44 =75.4GPa for copper, and C 11 =246.0GPa, C 12 =134GPa and C 44 =28.7GPa for niobium. The x-axis is parallel to Cu and [1][2][3][4][5][6][7][8][9][10][11][12] Nb , the z-axis parallel to [111] Cu and [110] Nb , and the y-axis pointing into the paper and parallel to [-110] Cu and [1-1-1] Nb . The stress component σ 13 is shown in Figure 3.…”

Section: The Numerical Simulation For Dislocation Core Spreading At Cu/nb Interfacementioning

confidence: 99%

“…On the one hand, interface acting as sources, may nucleate and emit dislocations, which facilitates the propagation of plastic deformation from one grain to the adjacent grain [1]. On the other hand, interface acting as barriers, can postpone or block dislocation transmission from one crystal to the other, which strengthens the material [2]. The concept of the weak-interface strengthening mechanism has been proposed and demonstrated in metallic multilayer [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

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Interface Dislocation Core-Spreading Simulation and Corresponding Response

Zhang¹,

Liu²,

Chu³

et al. 2017

dtetr

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Dislocation can spread its core at an interface especially at a weak shear interface associated with shearing the interface. Such core-spreading dislocation can significantly reduce stress/strain concentration compared with the compact dislocation and thus trap the dislocation in the interface, correspondingly strengthening materials. Employing the Green's function for a compact dislocation, we derived analytical expressions for the elastic fields of a dislocation with core spreading in anisotropic bimaterials. We proposed a conic model to mimic the spreading core of a dislocation at an interface. The accuracy and efficiency of the conic model are validated by the boundary conditions of both traction and displacement across the interface. Numerical simulation is calculated in the Cu/Nb biomaterial. The results of displacement and stress fields show that: (1) core-spreading dislocation can greatly reduce the stress intensity near the dislocation compared with the dislocation with a condensed core; (2) dislocation core spreading has a great influence on the elastic fields near the core region, while the influence can be negligible when the distance of a field point from the center of the dislocation core is greater than 1.51 times the width of the spreading core;(3) near the core region, Peach-Koehler force induced by the core spreading dislocation is larger than that of the compact dislocation.

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Section: The Numerical Simulation For Dislocation Core Spreading At Cu/nb Interfacementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Interface Dislocation Core-Spreading Simulation and Corresponding Response

Zhang¹,

Liu²,

Chu³

et al. 2017

dtetr

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“…[31][32][33][34][35] With this advantage, the PFM model of dislocation shows great potential in modeling dislocation intersections.…”

Section: Introductionmentioning

confidence: 99%

“…9 Different from the DDD techniques that require priori rules as inputs, 10 another simulation method also based on continuum elastic theory called phase field model (PFM) [25][26][27][28][29][30] can straightforwardly account for the effects of short-range core reactions by incorporating the generalized stacking fault energy (γ-surface) 11 from atomistic or first principle calculations, such as dislocation dissociation. [31][32][33][34][35] With this advantage, the PFM model of dislocation shows great potential in modeling dislocation intersections.…”

Section: Introductionmentioning

confidence: 99%

Improved phase field model of dislocation intersections

Zheng

et al. 2018

npj Comput Mater

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Revealing the long-range elastic interaction and short-range core reaction between intersecting dislocations is crucial to the understanding of dislocation-based strain hardening mechanisms in crystalline solids. Phase field model has shown great potential in modeling dislocation dynamics by both employing the continuum microelasticity theory to describe the elastic interactions and incorporating the γ-surface into the crystalline energy to enable the core reactions. Since the crystalline energy is approximately formulated by linear superposition of interplanar potential of each slip plane in the previous phase field model, it does not fully account for the reactions between dislocations gliding in intersecting slip planes. In this study, an improved phase field model of dislocation intersections is proposed through updating the crystalline energy by coupling the potential of two intersecting planes, and then applied to study the collinear interaction followed by comparison with the previous simulation result using discrete dislocation dynamics. Collinear annihilation captured only in the improved phase field model is found to strongly affect the junction formation and plastic flow in multislip systems. The results indicate that the improvement is essential for phase field model of dislocation intersections. INTRODUCTIONInteractions between dislocations gliding in intersecting slip planes play fundamental roles in the strain hardening during plastic deformation of crystalline materials.1-4 Dislocation intersections lead to the formation of dislocation junctions in minimum energy configurations. In face-centered cubic (FCC) crystals, the sessile junction known as Lomer-Cottrell lock 5,6 is assumed to be the most stable barrier to further dislocation motion in the traditional view.1,3 However, Madec and co-workers 7 reported that the interaction between two intersecting dislocations with collinear Burgers vectors is the strongest of all dislocation reactions. Previous modeling and simulations 7-24 on investigating the dislocation intersections emphasized the importance of the interaction details between individual dislocations, including not only the long-range elastic interactions but also the short-range core reactions. Most of these researches suggested that the dislocation interactions can be studied by multiscale approaches, where the discrete dislocation dynamics (DDD) based on continuum elasticity theory deals with the long-range elastic attraction or repulsion, and atomistic simulations the short-range reaction rules.9 Different from the DDD techniques that require priori rules as inputs, 10 another simulation method also based on continuum elastic theory called phase field model (PFM) 25-30 can straightforwardly account for the effects of short-range core reactions by incorporating the generalized stacking fault energy (γ-surface) 11 from atomistic or first principle calculations, such as dislocation dissociation. [31][32][33][34][35] With this advantage, the PFM model of dislocation shows great potent...

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