Electronic origin of solid solution softening in bcc molybdenum alloys

N. I. Medvedeva, Yu N. Gornostyrev, Arthur J Freeman

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26 Citations (Scopus)

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 languageEnglish
Article number136402
JournalPhysical Review Letters
Volume94
Issue number13
DOIs
Publication statusPublished - Apr 8 2005

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molybdenum alloys
stacking fault energy
softening
solid solutions
electronics
alloying
electrons
transition metals
nucleation
electronic structure
augmentation

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 journalArticle

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