Interactions between basal dislocations and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg"><mml:msubsup><mml:mi>β</mml:mi><mml:mn>1</mml:mn><mml:mo>′</mml:mo></mml:msubsup></mml:math> precipitates in Mg–4Zn alloy: Mechanisms and strengthening

Alizadeh, Reza; LLorca, J.

doi:10.1016/j.actamat.2020.01.028

Cited by 75 publications

(13 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although these models were able to rationalize some of the experimental trends, it should be noticed that the Orowan model assumes a very simplistic approach for the dislocation/precipitate interaction: the precipitates are rigid obstacles overcome by dislocations by the formation of an Orowan loop. Nevertheless, recent micropillar compression tests in Mg-5 wt% Zn alloys [17,18] have shown evidence of precipitate shearing basal dislocations and similar results were found in transmission electron microscopy observations of dislocation/precipitate interactions in Mg-Al alloys [19,20]. Thus, simulations at smaller length scales (either using dislocation dynamics [21][22][23][24] or molecular mechanics [22,[25][26][27][28][29]) are required to get a better understanding of the physics and to develop more accurate models.…”

Section: Introductionmentioning

confidence: 70%

Basal dislocation/precipitate interactions in Mg–Al alloys: an atomistic investigation

Esteban-Manzanares

Papadimitriou

et al. 2019

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

The interaction between edge basal dislocations and β-Mg 17 Al 12 precipitates was studied using atomistic simulations. A strategy was developed to insert a lozenge-shaped Mg 17 Al 12 precipitate with Burgers orientation relationship within the Mg matrix in an atomistic model ensuring that the matrix/precipitate interfaces were close to minimum energy configurations. It was found that the dislocation bypassed the precipitate by the formation of an Orowan loop, that entered the precipitate. Within the precipitate, the dislocation was not able to progress further until more dislocations overcome the precipitate and push the initial loop to shear the precipitate along the (110) plane, parallel to the basal plane of Mg. This process was eventually repeated as more dislocations overcome the precipitate and this mechanism of dislocation/precipitate interaction was in agreement with experimental observations. Moreover, the initial resolved shear stress to bypass the precipitate was in agreement with the predictions of the Bacon-Kocks-Scattergood model.

show abstract

Section: Introductionmentioning

confidence: 70%

Basal dislocation/precipitate interactions in Mg–Al alloys: an atomistic investigation

Esteban-Manzanares

Papadimitriou

et al. 2019

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

show abstract

“…The critical resolved shear stress for twinning (CRSStwinning), calculated as the product between the yield strength (195 MPa) and SFtwinning, amounts to 96 MPa. This value is significantly higher than that measured in pure Mg by single crystal studies, which amounts approximately to 12 MPa [72], and by micropillar studies, which range from 20 to 70 MPa.…”

Section: Refcontrasting

confidence: 55%

“…Mg Alloy (wt.%) CRSSbasal (MPa) [155] Pure Mg (Single cristal) 4 [158] Pure Mg (Micropillar) 6 [71] Mg-1Mn-1Nd, aged (Micropillar, prismatic plates) 31 [157] Mg-5Gd-2Y-0.3Zr, aged (Micropillar, prismatic disks) 35 [72] Mg-5Zn, aged 149ºC (Micropillar, c-axis rods) 55 [72] Mg-5Zn, aged 204ºC (Micropillar, c-axis rods) In the following, the micromechanical study conducted in grain 2, in which the basal plane forms an angle of 84° with respect to the compression axis, and where therefore twinning is expected to be the main strain carrier upon yielding (SF twinning = 0.4933), will be described. In this grain, the compression axis is close to the [01-10] direction.…”

Section: Refmentioning

confidence: 99%

Influence of Al and Zn alloying additions on the deformation mechanisms of Mg alloys

Shi¹

View full text Add to dashboard Cite

show abstract

“…It is caused by the block dislocation motion of the precipitated phases, which determines the strength of the alloy. Experiments show that the dislocations overcome the precipitates by shearing [ 8–10 ] and Orowan‐bypassing mechanism. [ 11,12 ] As the precipitate size increases, the Orowan strengthening effect decreases.…”

Section: Introductionmentioning

confidence: 99%

Mechanism on Material Strengthening of Metastable Precipitate and Edge Dislocation in Al–Mg–Si Alloy

Kong

Liu²,

Zhang

2023

Physica Status Solidi (b)

View full text Add to dashboard Cite

The metastable precipitate β″ plays a key role in material strengthening in Al–Mg–Si alloys. To investigate the mechanism on material strengthening of metastable precipitates, the interaction between β″ metastable precipitates and edge dislocations is studied using molecular dynamics. It is indicated in the results that the precipitate can be overcome by shearing without the formation of Orowan loops in case of smaller precipitate sizes. By increasing the temperature and reducing the shear strain rate, the critical resolved shear stress (CRSS) can be decreased. Larger precipitate sizes can lead to higher CRSS due to larger interaction area. Shear deformation can be clearly found on the precipitate when dislocations interact with the precipitate. When newly generated dislocations further interact with the sheared precipitate, the strengthening can be reduced due to the smaller cut width. This is the reason that strain hardening decreases with the increase of plastic deformation in macro scale.

show abstract

Interactions between basal dislocations and β1′ precipitates in Mg–4Zn alloy: Mechanisms and strengthening

Cited by 75 publications

References 49 publications

Basal dislocation/precipitate interactions in Mg–Al alloys: an atomistic investigation

Basal dislocation/precipitate interactions in Mg–Al alloys: an atomistic investigation

Influence of Al and Zn alloying additions on the deformation mechanisms of Mg alloys

Mechanism on Material Strengthening of Metastable Precipitate and Edge Dislocation in Al–Mg–Si Alloy

Contact Info

Product

Resources

About