Electronic origin of solid solution softening in bcc molybdenum alloys

N. I. Medvedeva*, Yu N. Gornostyrev, A. J. Freeman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

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 (US)
Article number136402
JournalPhysical review letters
Volume94
Issue number13
DOIs
StatePublished - Apr 8 2005

ASJC Scopus subject areas

  • General Physics and Astronomy

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