Dislocation-particle interactions in magnesium alloys

Wang, C.; Cepeda-Jiménez, C.M.; Pérez‐Prado, M.T.

doi:10.1016/j.actamat.2020.04.055

Cited by 49 publications

(18 citation statements)

References 36 publications

(126 reference statements)

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“…This is valid for the T6 and for the TT conditions and is typical of the presence of solutes and the phenomenon of dynamic strain aging at relative low temperatures. Additionally, the remarkably low precipitate strengthening in magnesium alloys is well known [29][30][31], while solute strengthening has a more important role for understanding the mechanical properties in magnesium alloys than in other alloy systems [32]. This relative low influence of precipitates occurs at both low and high temperatures.…”

Section: Deformation Mechanismsmentioning

confidence: 99%

Large elongations in WE54 magnesium alloy by solute-drag creep controlling the deformation behavior

Ruano¹,

Álvarez-Leal²,

Orozco‐Caballero³

et al. 2020

Materials Science and Engineering: A

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Solute-drag creep is a diffusion-controlled process that may govern deformation in coarse-grained materials with solute atoms in solution. Elongation-to-failure tensile tests were conducted in a WE54 alloy containing solutes of Y and Nd in the range 25 to 450 ºC. Elongations of more than 150% were observed at high temperatures and a maximum elongation to failure of 312% was determined at 450 ºC and 10-2 s-1. Microstructural observations show elongated grains and the presence of dislocation bands after deformation under these conditions. Strain-rate-change tests reveal a range at high temperatures showing low stress exponents. Since grain boundary sliding was discarded as a possible controlling mechanism, the observed low stress exponents, high elongations and elongated grains are attributed to solute-drag creep as the principal deformation mechanism.

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Section: Deformation Mechanismsmentioning

confidence: 99%

Large elongations in WE54 magnesium alloy by solute-drag creep controlling the deformation behavior

Ruano¹,

Álvarez-Leal²,

Orozco‐Caballero³

et al. 2020

Materials Science and Engineering: A

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“…Magnesium and its alloys have received significant research attention owing to the lightweight structure, recyclability and abundance [1][2][3]. However, a wide range of applications of the magnesium alloys is restricted due to their poor formability near room temperature and relatively low mechanical properties in contrast to the conventional structural materials, e.g., steels and aluminum alloys.…”

Section: Introductionmentioning

confidence: 99%

Improve the Mechanical Properties of Mg–3Al–1Zn Alloy via Simultaneous Annealing and Loading

2022

Metals

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A strengthening phenomenon has been demonstrated in the Mg–3Al–1Zn (AZ31) alloy after simultaneous annealing and loading at 180 °C. The microstructural analysis reveals that a few second-phase particles appear in the material after direct annealing at 180 °C for 20 h. However, a higher quantity of the second-phase particles (Al12Mg17) is observed in the alloy after simultaneous annealing and loading. Further, a high stress is observed to be more beneficial for the precipitation of the particles. It is speculated that the stress applied during annealing can provide a better condition for the nucleation of the precipitates. The enhanced extent of precipitates may play a significant role in preventing the dislocation gliding, thus, leading to a strengthening effect. The observed phenomenon may also provide a novel strategy for strengthening the magnesium alloys.

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“…During the past decades, the Orowan stress calculations based on the model developed by Bacon, Kocks and Scattergood (the BKS model) [1] were successful in the scenario of lattice dislocations (LDs) bypassing non-shearable precipitates in metallic alloys. The bowed-out LDs between precipitates before bypassing can be observed by experimental techniques such as transmission electron microscopy (TEM) [2][3][4] and simulation techniques such as molecular dynamics (MD) [5][6][7]. In lightweight, energy-efficient magnesium (Mg) alloys, the BKS model was also applied to calculate the Orowan stress needed by twinning dislocations (TDs), which are shear-driven line-defects and manipulate the behavior of a twin [8,9].…”

Section: Introductionmentioning

confidence: 99%

“…Unfortunately, the Orowan stress is hard to measure in experiments because the back-stress exists in the strengthening against twins [17,18], and the back-stress cannot be precisely calculated due to the local plastic relaxation [17,19]. Therefore, although the total strengthening against twins can be measured [2,3,20,21], it is not known how much of the strengthening is due to the Orowan stress. Therefore, validating the numerical accuracy of the BKS model for TD needs other approaches than experimental means.…”

Section: Introductionmentioning

confidence: 99%

The Orowan Stress Measurement of Twinning Dislocations in Magnesium

Tang

Guo

2021

Metals

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The interaction between a lattice dislocation and non-shearable precipitates has been well explained by the Orowan bypass mechanism. The calculated additional shear stress facilitates the evaluation of precipitation hardening in metallic alloys. The lack of information about how a twinning dislocation behaves in the same scenario hinders our understanding of the strengthening against twin-mediated plasticity in magnesium alloys. In the current study, the bowing and bypassing of a twining dislocation impeded by impenetrable obstacles are captured by atomistic simulations. The Orowan stress measurement is realized by revealing the stick-slip dynamics of a twinning dislocation. The measured Orowan stress significantly deviate from what classic theory predicts. This deviation implies that the line tension approximation may generally overestimate the Orowan stress for twinning dislocations.

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Dislocation-particle interactions in magnesium alloys

Cited by 49 publications

References 36 publications

Large elongations in WE54 magnesium alloy by solute-drag creep controlling the deformation behavior

Large elongations in WE54 magnesium alloy by solute-drag creep controlling the deformation behavior

Improve the Mechanical Properties of Mg–3Al–1Zn Alloy via Simultaneous Annealing and Loading

The Orowan Stress Measurement of Twinning Dislocations in Magnesium

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