Effect of stacking-fault energy on deformation twin thickness in Cu–Al alloys

Indenter size effect on the reversible incipient plasticity of Al (001) surface is studied by quasicontinuum simulations. Two cylindrical indenters with the radii 2.5nm and 17.5nm are used to penetrate the surface respectively, in displacement-control in steps of 0.02 nm. Results show that the plasticity under the small indenter is reversible, since it is dominated by the nucleation of a thin deformation twin, which can be fully removed after withdrawal of the indenter, due to the imaging force and stacking fault energy. Under the large indenter, multiple slip systems are activated simultaneously when incipient plasticity occurs, a few twin, dislocation and stacking fault ribbons still remain under the surface when the indenter has been completely retracted, thus the plasticity is irreversible.

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Correlation of Grain Size, Stacking Fault Energy, and Texture in Cu-Al Alloys Deformed under Simulated Rolling Conditions

Advances in Materials Science and Engineering ◽

10.1155/2015/953130 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 5

Author(s):

Ehab A. El-Danaf ◽

Mahmoud S. Soliman ◽

Ayman A. Al-Mutlaq

Keyword(s):

Grain Size ◽

Strain Hardening ◽

Mechanical Twinning ◽

Al Alloys ◽

Stacking Fault ◽

Stacking Fault Energy ◽

Wide Range ◽

Orientation Density ◽

Pure Cu ◽

Strain Hardening Rate

The effect of grain size and stacking fault energy (SFE) on the strain hardening rate behavior under plane strain compression (PSC) is investigated for pure Cu and binary Cu-Al alloys containing 1, 2, 4.7, and 7 wt. % Al. The alloys studied have a wide range of SFE from a low SFE of 4.5 mJm−2for Cu-7Al to a medium SFE of 78 mJm−2for pure Cu. A series of PSC tests have been conducted on these alloys for three average grain sizes of ~15, 70, and 250 μm. Strain hardening rate curves were obtained and a criterion relating twinning stress to grain size is established. It is concluded that the stress required for twinning initiation decreases with increasing grain size. Low values of SFE have an indirect influence on twinning stress by increasing the strain hardening rate which is reflected in building up the critical dislocation density needed to initiate mechanical twinning. A study on the effect of grain size on the intensity of the brass texture component for the low SFE alloys has revealed the reduction of the orientation density of that component with increasing grain size.

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The Influence of Solute Atoms on the Stacking Fault Energy in αCu–Al Alloys

Transactions of the Japan Institute of Metals ◽

10.2320/matertrans1960.15.39 ◽

1974 ◽

Vol 15 (1) ◽

pp. 39-45 ◽

Cited By ~ 17

Author(s):

Yoshitsugu Tomokiyo ◽

Kunio Kaku ◽

Tetsuo Eguchi

Keyword(s):

Al Alloys ◽

Stacking Fault ◽

Stacking Fault Energy ◽

Solute Atoms

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The influence of stacking fault energy on the mechanical properties of nanostructured Cu and Cu–Al alloys processed by high-pressure torsion

Scripta Materialia ◽

10.1016/j.scriptamat.2011.01.041 ◽

2011 ◽

Vol 64 (10) ◽

pp. 954-957 ◽

Cited By ~ 92

Author(s):

X.H. An ◽

Q.Y. Lin ◽

S.D. Wu ◽

Z.F. Zhang ◽

R.B. Figueiredo ◽

...

Keyword(s):

Mechanical Properties ◽

High Pressure ◽

High Pressure Torsion ◽

Al Alloys ◽

Stacking Fault ◽

Stacking Fault Energy

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Influence of stacking-fault energy on the accommodation of severe shear strain in Cu-Al alloys during equal-channel angular pressing

Journal of Materials Research ◽

10.1557/jmr.2009.0426 ◽

2009 ◽

Vol 24 (12) ◽

pp. 3636-3646 ◽

Cited By ~ 46

Author(s):

Xianghai An ◽

Qingyun Lin ◽

Shen Qu ◽

Gang Yang ◽

Shiding Wu ◽

...

Keyword(s):

Shear Strain ◽

Equal Channel Angular Pressing ◽

Shear Bands ◽

Al Alloys ◽

Stacking Fault ◽

Stacking Fault Energy ◽

Dislocation Slip ◽

Al Alloy ◽

Angular Pressing ◽

Inherent Deformation

X-ray diffraction (XRD) and transmission electron microscope (TEM) investigations have been carried out to decode the influence of stacking-fault energy (SFE) on the accommodation of large shear deformation in Cu-Al alloys subjected to one-pass equal-channel angular pressing. XRD results exhibit that the microstrain and density of dislocations initially increased with the reduction in the SFE, whereas they sharply decreased with a further decrease in SFE. By systematic TEM observations, we noticed that the accommodation mechanism of intense shear strain was gradually transformed from dislocation slip to deformation twin when SFE was lowered. Meanwhile, twin intersections and internal twins were also observed in the Cu-Al alloy with extremely low SFE. Due to the large external plastic deformation, microscale shear bands, as an inherent deformation mechanism, are increasingly significant to help carry the high local plasticity because low SFE facilitates the formation of shear bands.

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