Dislocation Dynamics and Plasticity

Yoshinaga, Hideo; Takeuchi, Shin; Suzuki, Takaya

doi:10.1007/978-3-642-75774-7

Cited by 223 publications

(180 citation statements)

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“…In particular, in this model the effect of increasing (decreasing) the strain rate has an analogous effect to decreasing (increasing) the temperature, and vice-versa, as noted by Tang et al [24]. In the regime of very high strain-rates (γ > 10 5 s −1 ), effects such as electron and phonon drag become important and control the velocity of dislocations [25,26].…”

Section: Dislocation Mobility: Double-kink Formation and Thermally Acmentioning

confidence: 64%

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Cuitiño

Stainier

Wang

et al. 2001

Journal of Computer-Aided Materials Design

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In this paper we present a modeling approach to bridge the atomistic with macroscopic scales in crystalline materials. The methodology combines identification and modeling of the controlling unit processes at microscopic level with the direct atomistic determination of fundamental material properties. These properties are computed using a many body Force Field derived from ab initio quantum-mechanical calculations. This approach is exercised to describe the mechanical response of high-purity Tantalum single crystals, including the effect of temperature and strain-rate on the hardening rate. The resulting atomistically informed model is found to capture salient features of the behavior of these crystals such as: the dependence of the initial yield point on temperature and strain rate; the presence of a marked stage I of easy glide, specially at low temperatures and high strain rates; the sharp onset of stage II hardening and its tendency to shift towards lower strains, and eventually disappear, as the temperature increases or the strain rate decreases; the parabolic stage II hardening at low strain rates or high temperatures; the stage II softening at high strain rates or low temperatures; the trend towards saturation at high strains; the temperature and strain-rate dependence of the saturation stress; and the orientation dependence of the hardening rate.

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Section: Dislocation Mobility: Double-kink Formation and Thermally Acmentioning

confidence: 64%

Untitled

Cuitiño

Stainier

Wang

et al. 2001

Journal of Computer-Aided Materials Design

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“…The former must take place at stresses approaching zero and as the stress increases the transition to the latter occurs. In the low-stress regime the fully developed kinks interact elastically via the attractive Eshelby potential that is in the framework of the isotropic elasticity equal to !µ a 0 2 b 2 / 8"#z [13,15], where µ is the shear modulus, b the magnitude of the Burgers vector, a 0 the height of the kinks or, equivalently, the distance between two neighboring Peierls valleys in the slip plane, and !z their separation. The applicability of the elastic treatment of the kink-pairs was demonstrated in atomistic studies of Duesbery [37,38].…”

Section: Mesoscopic Dislocation Models Of Kink-pair Formationmentioning

confidence: 99%

“…This process results in the dislocation glide in the direction of the kink formation [11][12][13]. Following the standard transition state theory of thermally activated processes (see for example [14,15]) the velocity of the dislocation is then…”

Section: Introductionmentioning

confidence: 99%

“…! 0 are the pre-exponential factors depending on the details of the mechanism of kink-pair formation that vary only weakly with the applied stress [11][12][13][14][15]. The yield stress, !…”

Section: Introductionmentioning

confidence: 99%

“…does work during the activation process, but other constituents of the activation enthalpy may depend on the full stress tensor. This model has been very successful in theoretical treatments of a number of dislocation phenomena involving the lattice resistance to the dislocation glide [13], such as internal friction (Bordoni peak) [1,16,17], thermally activated glide in semiconductors where the high lattice friction arises owing to the covalent bonds [18][19][20] and thermally activated glide of screw dislocations in BCC metals [2,21,22]. The models of the formation of kink-pairs assume implicitly that the Peierls barrier can be identified with the potential energy that varies periodically with the position of the dislocation in its slip plane.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Multiscale modeling of plastic deformation of molybdenum and tungsten. III. Effects of temperature and plastic strain rate

Gröger

Vítek

2008

Acta Materialia

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In this paper we develop a link between the atomic-level modeling of the glide of 1/2〈111〉 screw dislocations at 0 K and the thermally activated motion of these dislocations via nucleation of pairs of kinks. For this purpose, we introduce the concept of a hypothetical Peierls barrier, which reproduces all the aspects of the dislocation glide at 0 K resulting from the complex response to non-glide stresses and expressed in a compact form by the yield criteria advanced in Part II. To achieve this the barrier is dependent not only on the crystal symmetry and interatomic bonding but also on the applied stress tensor. Standard models are then employed to evaluate the activation enthalpy of kink-pairs formation, which is now also a function of the full applied stress tensor. The transition states theory links then this mechanism with the temperature and strain rate dependence of the yield stress.

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Dislocations in Crystals

Kelly

Knowles

2012

Crystallography and Crystal Defects

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Dislocation Dynamics and Plasticity

Cited by 223 publications

References 0 publications

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Multiscale modeling of plastic deformation of molybdenum and tungsten. III. Effects of temperature and plastic strain rate

Dislocations in Crystals

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