Abstract
The intrinsic mechanism of solid solution softening in bcc molybdenum alloys due to 5d transition metal additions is investigated on the basis of ab initio electronic-structure calculations that model the effect of alloying elements on the generalized stacking fault (GSF) energies. We demonstrate that additions with an excess of electrons (Re, Os, Ir, and Pt) lead to a decrease in the GSF energy and those with a lack of electrons (Hf and Ta) to its sharp increase. Using the generalized Peierls-Nabarro model for a nonplanar core, we associate the local reduction of the GSF energy with an enhancement of double kink nucleation and an increase of the dislocation mobility, and we reveal the electronic reasons for the observed dependence of the solution softening on the atomic number of the addition.
| Original language | English |
|---|---|
| Article number | 136402 |
| Journal | Physical Review Letters |
| Volume | 94 |
| Issue number | 13 |
| DOIs | |
| Publication status | Published - Apr 8 2005 |
Fingerprint
ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Electronic origin of solid solution softening in bcc molybdenum alloys. / Medvedeva, N. I.; Gornostyrev, Yu N.; Freeman, Arthur J.
In: Physical Review Letters, Vol. 94, No. 13, 136402, 08.04.2005.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Electronic origin of solid solution softening in bcc molybdenum alloys
AU - Medvedeva, N. I.
AU - Gornostyrev, Yu N.
AU - Freeman, Arthur J
PY - 2005/4/8
Y1 - 2005/4/8
N2 - The intrinsic mechanism of solid solution softening in bcc molybdenum alloys due to 5d transition metal additions is investigated on the basis of ab initio electronic-structure calculations that model the effect of alloying elements on the generalized stacking fault (GSF) energies. We demonstrate that additions with an excess of electrons (Re, Os, Ir, and Pt) lead to a decrease in the GSF energy and those with a lack of electrons (Hf and Ta) to its sharp increase. Using the generalized Peierls-Nabarro model for a nonplanar core, we associate the local reduction of the GSF energy with an enhancement of double kink nucleation and an increase of the dislocation mobility, and we reveal the electronic reasons for the observed dependence of the solution softening on the atomic number of the addition.
AB - The intrinsic mechanism of solid solution softening in bcc molybdenum alloys due to 5d transition metal additions is investigated on the basis of ab initio electronic-structure calculations that model the effect of alloying elements on the generalized stacking fault (GSF) energies. We demonstrate that additions with an excess of electrons (Re, Os, Ir, and Pt) lead to a decrease in the GSF energy and those with a lack of electrons (Hf and Ta) to its sharp increase. Using the generalized Peierls-Nabarro model for a nonplanar core, we associate the local reduction of the GSF energy with an enhancement of double kink nucleation and an increase of the dislocation mobility, and we reveal the electronic reasons for the observed dependence of the solution softening on the atomic number of the addition.
UR - http://www.scopus.com/inward/record.url?scp=18144393472&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=18144393472&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.94.136402
DO - 10.1103/PhysRevLett.94.136402
M3 - Article
VL - 94
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 13
M1 - 136402
ER -