Effect of equal channel angular pressing on the Portevin–Le Chatelier effect in an Al3Mg alloy

Lebedkina, Tatiana; Lebyodkin, M.A.; Lamark, Torbjorn; Janeček, Miloš; Estrin, Yuri

doi:10.1016/j.msea.2014.07.064

Cited by 43 publications

(24 citation statements)

References 31 publications

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“…Furthermore, such extreme treatment effectively suppresses serrated behavior (cf. Lebedkina et al, 2014), in agreement with the vanishing SRS. Only sporadic serrations were observed before the onset of necking (e.g., curve 3 in Fig.…”

Section: Deformation Curvessupporting

confidence: 80%

“…The effects of precipitation and grain-boundary strengthening on mechanical properties and the PLC instability in AlMg alloys have been intensely discussed in the literature (Robinson, 1994;Joshi et al, 2009;Lebedkina et al, 2014;Mogucheva et al, 2016;Yuzbekova et al, 2017;. The following discussion will be devoted to the relationship between the PLC effect and the necking instability.…”

Section: Fulfillment Of the Considère Criterion In The Presence Of Jementioning

confidence: 99%

“…Not only complementary types are sometimes defined to distinguish some rarer variants of shape of deformation curves associated with the propagation mode, e.g., step-wise curves of type D differing from type A shape by the absence of stress falls (Rodriguez, 1984). Besides, real behaviors often display combinations of types, especially in practically used alloys with complex compositions and initial microstructures (Robinson, 1994;Lebedkina et al, 2014Lebedkina et al, , 2017Andreau et al, 2014;Mogucheva et al, 2016;Valdes-Tabernero et al, 2017). Such a diversity makes difficult the rationalization of various effects of the PLC instability on mechanical behavior of alloys and their relationships with the onset of necking and its progression until failure of tensile samples.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interrelation between the Portevin Le-Chatelier effect and necking in AlMg alloys

Zhemchuzhnikova

Lebyodkin

Yuzbekova

et al. 2018

International Journal of Plasticity

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Plastic flow instability caused by the Portevin Le-Chatelier (PLC) effect and its influence on the necking instability were studied in a binary and a precipitation-strengthened AlMg alloy using the digital image correlation (DIC) technique. Coarse-grained structure and two different fine-grained states distinctly distinguished by dislocation density were produced in both alloys using similar routes of thermomechanical processing. The patterns of stress serrations and strain localization observed at different strain rates include virtually all common types of behavior of the PLC effect. Besides, particular spatiotemporal patterns testifying to a concurrency between the propagation and localization of deformation bands are detected at low strain rates. Despite this diversity, the analysis of deformation curves with smoothened-out serrations bears evidence that the onset of necking always corresponds to the geometric Considère condition. Nevertheless, visualization of the evolution of the local strain-rate field using DIC indicates that the two mechanisms of plastic instability are closely interrelated and modify each other's behavior. The neck formation is associated with a progressive immobilization of the PLC bands, ending by the ultimate strain localization. The coexistence of two kinds of instability during necking gives rise to specific spatiotemporal patterns including oscillatory strain localization.

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Section: Deformation Curvessupporting

confidence: 80%

Section: Fulfillment Of the Considère Criterion In The Presence Of Jementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Interrelation between the Portevin Le-Chatelier effect and necking in AlMg alloys

Zhemchuzhnikova

Lebyodkin

Yuzbekova

et al. 2018

International Journal of Plasticity

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show abstract

“…For example, the preliminary data on the effect of grain refinement on the PLC instability in the alloy studied in [21] bear evidence that the mode of continuous propagation may persist after ECAP [47]. On the other hand, the suppression of the PLC effect after ECAP of a binary alloy was explained in [26] in terms of the worsening of the conditions for synchronization of dislocations.…”

Section: Discussionmentioning

confidence: 99%

“…This trend agrees with the requirement of negative strain-rate sensitivity (SRS) in the DSA theory, as a necessary condition of plastic instability. However, the strength variation between samples was considerable, especially after ECAP [24][25][26][27][28]. Consequently, quantitative estimations of the SRS were not performed in the present work.…”

Section: Stress Serrations Patternsmentioning

confidence: 91%

Peculiar Spatiotemporal Behavior of Unstable Plastic Flow in an AlMgMnScZr Alloy with Coarse and Ultrafine Grains

Lebyodkin

Lebedkina

Mogucheva

et al. 2017

Metals

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Abstract:The work addresses the effects of nanosize particles and grain refinement on the patterns of stress serrations and kinematics of deformation bands associated with the Portevin-Le Chatelier instability of plastic flow. Ultra-fine-grained microstructure was obtained using equal-channel angular pressing of the initial coarse-grained alloy. Tensile tests were carried out on flat specimens at strain rates in the range from 3 × 10 −5 to 1.4 × 10 −2 s −1 . Using local extensometry techniques, it was found that the presence of nanoscale precipitates promotes quasi-continuous propagation of deformation bands in the entire strain-rate range. The grain refinement leads to a transition to relay-race propagation at high strain rates and static strain localization at low rates. The results are discussed from the viewpoint of competition between various dynamical modes of plastic deformation associated with collective dynamics of dislocations.

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Serrated Flow in Alloy Systems

Lebyodkin

Lebedkina

Brechtl

et al. 2021

High-Entropy Materials: Theory, Experiments, and Applications

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Effect of equal channel angular pressing on the Portevin–Le Chatelier effect in an Al3Mg alloy

Cited by 43 publications

References 31 publications

Interrelation between the Portevin Le-Chatelier effect and necking in AlMg alloys

Interrelation between the Portevin Le-Chatelier effect and necking in AlMg alloys

Peculiar Spatiotemporal Behavior of Unstable Plastic Flow in an AlMgMnScZr Alloy with Coarse and Ultrafine Grains

Serrated Flow in Alloy Systems

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