Abstract
Twinning is one of most prevalent deformation mechanisms in materials. Having established a quantitative theory to predict onset twinning stress τcrit in fcc elemental metals from their generalized planar-fault-energy (GPFE) surface, we exemplify its use in alloys where the Suzuki effect (i.e., solute energetically favors residing at and near planar faults) is operative; specifically, we apply it in Cu-xAl (x is 0, 5, and 8.3 at.%) in comparison with experimental data. We compute the GPFE via density-functional theory, and we predict the solute dependence of the GPFE and τcrit, in agreement with measured values. We show that τcrit correlates monotonically with the unstable twin fault energies (the barriers to twin nucleation) rather than the stable intrinsic stacking-fault energies typically suggested. We correlate the twinning behavior and electronic structure with changes in solute content and proximity to the fault planes through charge-density redistribution at the fault and changes to the layer- and site-resolved density of states, where increased bonding charge correlates with decrease in fault energies and τcrit.
| Original language | English (US) |
|---|---|
| Article number | 214202 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 79 |
| Issue number | 21 |
| DOIs | |
| State | Published - Jun 4 2009 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
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Quantitative prediction of twinning stress in fcc alloys : Application to Cu-Al. / Kibey, Sandeep A.; Wang, L. L.; Liu, J. B.; Johnson, H. T.; Sehitoglu, H.; Johnson, D. D.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 79, No. 21, 214202, 04.06.2009.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Quantitative prediction of twinning stress in fcc alloys
T2 - Application to Cu-Al
AU - Kibey, Sandeep A.
AU - Wang, L. L.
AU - Liu, J. B.
AU - Johnson, H. T.
AU - Sehitoglu, H.
AU - Johnson, D. D.
PY - 2009/6/4
Y1 - 2009/6/4
N2 - Twinning is one of most prevalent deformation mechanisms in materials. Having established a quantitative theory to predict onset twinning stress τcrit in fcc elemental metals from their generalized planar-fault-energy (GPFE) surface, we exemplify its use in alloys where the Suzuki effect (i.e., solute energetically favors residing at and near planar faults) is operative; specifically, we apply it in Cu-xAl (x is 0, 5, and 8.3 at.%) in comparison with experimental data. We compute the GPFE via density-functional theory, and we predict the solute dependence of the GPFE and τcrit, in agreement with measured values. We show that τcrit correlates monotonically with the unstable twin fault energies (the barriers to twin nucleation) rather than the stable intrinsic stacking-fault energies typically suggested. We correlate the twinning behavior and electronic structure with changes in solute content and proximity to the fault planes through charge-density redistribution at the fault and changes to the layer- and site-resolved density of states, where increased bonding charge correlates with decrease in fault energies and τcrit.
AB - Twinning is one of most prevalent deformation mechanisms in materials. Having established a quantitative theory to predict onset twinning stress τcrit in fcc elemental metals from their generalized planar-fault-energy (GPFE) surface, we exemplify its use in alloys where the Suzuki effect (i.e., solute energetically favors residing at and near planar faults) is operative; specifically, we apply it in Cu-xAl (x is 0, 5, and 8.3 at.%) in comparison with experimental data. We compute the GPFE via density-functional theory, and we predict the solute dependence of the GPFE and τcrit, in agreement with measured values. We show that τcrit correlates monotonically with the unstable twin fault energies (the barriers to twin nucleation) rather than the stable intrinsic stacking-fault energies typically suggested. We correlate the twinning behavior and electronic structure with changes in solute content and proximity to the fault planes through charge-density redistribution at the fault and changes to the layer- and site-resolved density of states, where increased bonding charge correlates with decrease in fault energies and τcrit.
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U2 - 10.1103/PhysRevB.79.214202
DO - 10.1103/PhysRevB.79.214202
M3 - Article
AN - SCOPUS:67650092918
VL - 79
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 21
M1 - 214202
ER -