On the role of dislocation conservation in single-slip crystal plasticity

Metals in small volumes display a strong dependence on initial conditions, which translates into size effects and stochastic mechanical responses. In the context of crystal plasticity, this amounts to the role of pre-existing dislocation configurations that may emerge due to prior processing. Here, we study a minimal but realistic model of uniaxial compression of sub-micron finite volumes. We show how the statistical correlations of pre-existing dislocation configurations may influence the mechanical response in multi-slip crystal plasticity, in connection to the finite volume size and the initial dislocation density. In addition, spatial dislocation correlations display evidence that plasticity is strongly influenced by the formation of walls composed of bound dislocation dipoles.

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Role of strain-rate sensitivity in the crystal plasticity of hexagonal structures

International Journal of Plasticity ◽

10.1016/j.ijplas.2006.02.013 ◽

2007 ◽

Vol 23 (2) ◽

pp. 227-243 ◽

Cited By ~ 21

Author(s):

Benoît Beausir ◽

László S. Tóth ◽

Kenneth W. Neale

Keyword(s):

Strain Rate ◽

Strain Rate Sensitivity ◽

Crystal Plasticity ◽

Rate Sensitivity

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Dislocation patterning and recovery under single slip: modelling micromechanisms from observations

MRS Proceedings ◽

10.1557/proc-779-w1.4 ◽

2003 ◽

Vol 779 ◽

Author(s):

Patrick Veyssière ◽

Yu-Lung Chiu ◽

Fabienne Grégori

Keyword(s):

Cross Slip ◽

Nearest Neighbour ◽

Single Slip ◽

Slip Dislocation ◽

Diffusive Processes ◽

Dislocation Multiplication ◽

Double Cross

AbstractThe paper focuses on the formation and on the role of prismatic loops during deformation. The analysis is restricted to non-diffusive processes in fcc-related crystals. Double cross-slip and cross-slip dipolar annihilation yield strings of loops such that one loop extremity is aligned in the screw direction with the extremity of its nearest neighbour. Reactions between prismatic loops and mobile dislocations are at the origin of a number of microstructural reactions including recovery, dislocation entanglements and patterning in single slip, dislocation multiplication and there is indication that they may nucleate twins.

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Linking Meso- and Macroscale Simulations: Crystal Plasticity of hcp Metals and Plastic Potentials

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.1741 ◽

2007 ◽

Vol 539-543 ◽

pp. 1741-1746

Author(s):

Dirk Steglich ◽

Stéphane Graff ◽

Wolfgang Brocks

Keyword(s):

Slip System ◽

Single Crystals ◽

Crystal Plasticity ◽

Yield Function ◽

Crystal Plasticity Model ◽

Plastic Deformation Behavior ◽

Polycrystalline Aggregates ◽

Tension Compression Asymmetry ◽

Rolled Plates

A crystal plasticity model has been used to simulate channel die experiments on both, pure magnesium single crystals and polycrystalline textured rolled plates. Deformation mechanisms and slip system activity can be identified by FE-analyses of single crystals. The role of twinning can be understood and modeled phenomenologically by an additional slip system. Simulations of polycrystalline aggregates are used to obtain a representation of the material's phenomenological yield function in order to describe the plastic deformation behavior using the framework of continuum mechanics. This allows for accounting for the specific texture and thus for its optimization. The tension- compression asymmetry, which is typical for mechanically processed magnesium material, can be reproduced by means of the crystal plasticity and a phenomenological model.

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