Work hardening model based on multiple dislocation densities

Prasad, G.V.S.S.; Goerdeler, M.; Gottstein, Günter

doi:10.1016/j.msea.2005.03.061

Cited by 60 publications

(24 citation statements)

References 10 publications

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“…Unlike DDD which becomes handicapped at high strains, such a strategy would be well suited for large-strain problems with high quantities of dislocations, since any amount of dislocations can still be represented a dislocation density. The earlier group of dislocation-density models deals with discrete categories of dislocation density, such as mobile vs. immobile, cell-interior vs. cell-wall, and edge vs. screw (Roters et al, 2000;Prasad et al, 2005;Ma et al, 2006;Alankar et al, 2011;Vinogradov et al, 2012), but without considering the field nature of the dislocation densities and the conservative nature of their motion (Walgraef and Aifantis, 1985). A more sophisticated group of approach focuses primarily on the kinematics or dynamics of slip systems (Asaro and Rice, 1977) and their relationships to densities of dislocations.…”

Section: Introductionmentioning

confidence: 99%

A new dislocation-density-function dynamics scheme for computational crystal plasticity by explicit consideration of dislocation elastic interactions

Leung

Cheng

et al. 2015

International Journal of Plasticity

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a b s t r a c tCurrent strategies of computational crystal plasticity that focus on individual atoms or dislocations are impractical for real-scale, large-strain problems even with today's computing power. Dislocation-density based approaches are a way forward but a critical issue to address is a realistic description of the interactions between dislocations. In this paper, a new scheme for computational dynamics of dislocation-density functions is proposed, which takes full consideration of the mutual elastic interactions between dislocations based on the Hirth-Lothe formulation. Other features considered include (i) the continuity nature of the movements of dislocation densities, (ii) forest hardening, (iii) generation according to high spatial gradients in dislocation densities, and (iv) annihilation. Numerical implementation by the finite-volume method, which is well suited for flow problems with high gradients, is discussed. Numerical examples performed for a single-crystal aluminum model show typical strength anisotropy behavior comparable to experimental observations. Furthermore, a detailed case study on small-scale crystal plasticity successfully captures a number of key experimental features, including power-law relation between strength and size, low dislocation storage and jerky deformation.

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Section: Introductionmentioning

confidence: 99%

A new dislocation-density-function dynamics scheme for computational crystal plasticity by explicit consideration of dislocation elastic interactions

Leung

Cheng

et al. 2015

International Journal of Plasticity

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“…Describing the WH behavior in the above manner using a single dislocation density is also known as 'single parameter' approach and the concept has been found effective in describing the WH behavior of face-centered-cubic single crystal. However, instead of assuming a single dislocation density everywhere, considering various dislocation densities of different types of dislocations are reported to be helpful in modeling the WH phenomena in a polycrystalline alloy [3][4][5]. However, a 'single parameter' approach, which is based on a uniform dislocation density, is often good enough and simple to explain overall WH phenomena.…”

Section: Introductionmentioning

confidence: 99%

Role of dislocation density in raising the stage II work-hardening rate of Alloy 625

Mittra

Dubey

Kulkarni

et al. 2009

Materials Science and Engineering: A

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“…Studies [25,26] showed that when the dynamic recrystallization softening of the material occurs, the curve between the work hardening rate (h) and true stress (r) will exhibit inflection point, and the dynamic recrystallization critical strain (e c ) corresponds to the maximum value in dh/dr-r curve and the inflection point in h-r curve. Taking the true stress-strain curve of Nb-free steel obtained at a strain rate of 0.1 s -1 and 1200°C (see Fig.…”

Section: Calculation Of the Critical Strain Of Dynamic Recrystallizationmentioning

confidence: 99%

Effect of Nb Content on the Hot Deformation Behavior of S460ML Steel

Zhang

Meng

Yang

et al. 2018

Acta Metall. Sin. (Engl. Lett.)

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The hot deformation behavior of S460ML steel with different Nb contents was investigated by single-pass compression experiment on the Gleeble-1500 thermo-machine simulator at deformation temperatures ranging from 900 to 1200°C and strain rates from 0.1 to 5.0 s -1 . The critical strain of dynamic recrystallization (DRC) under different conditions was determined by using working hardening rate-strain curves. The relationship between critical strain and peak strain of DRC was discussed. By means of regression analysis method, the hot deformation activation energy of steels and the mathematical model for predicting DRC critical strain were calculated and established, respectively. The results showed that DRC occurred during hot deformation. As the deformation temperature increased and strain rate decreased, the critical strain of DRC decreased. The critical strain (e c ) showed linear relationship with peak strain (e p ). As Nb content increased, the needed deformation temperature for occurring DRC increased, while the needed strain rate for it decreased. The activation energy for hot deformation of S460ML steel increased with increasing Nb content.

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Work hardening model based on multiple dislocation densities

Cited by 60 publications

References 10 publications

A new dislocation-density-function dynamics scheme for computational crystal plasticity by explicit consideration of dislocation elastic interactions

A new dislocation-density-function dynamics scheme for computational crystal plasticity by explicit consideration of dislocation elastic interactions

Role of dislocation density in raising the stage II work-hardening rate of Alloy 625

Effect of Nb Content on the Hot Deformation Behavior of S460ML Steel

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