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Indexed by:Journal Papers

Date of Publication:2015-12-01

Journal:COMPUTATIONAL MATERIALS SCIENCE

Included Journals:SCIE

Volume:110

Page Number:163-168

ISSN No.:0927-0256

Key Words:Grain boundary; Impurities; First-principles; Vanadium; Embrittlement

Abstract:We studied the embrittling and strengthening effects of non-metallic (C, N, O, S, Si, and B) and metallic (Fe and Mo) interstitial impurities at a Sigma(3) (111) [1 (1) over bar0] grain boundary (GB) in vanadium (V) using first-principles calculations. All impurities incorporated into the GB are exothermic reaction except for Mo along with outward expansion of the GB space. Upon optimization, the small C, N, and O impurities at the GB prefer the same interstitial site, while the S, Si, B, Fe and Mo impurities prefer another interstitial site. According to strengthening energy calculations, C, N, B, and Fe act as the GB cohesion, while O and S are strong embrittlers as well Si and Mo are weak embrittlers. The analysis of atomic and electronic structures indicate that the embrittling and strengthening behavior of the impurities mainly depends on the bonding behavior of the impurity with surrounding vanadium atoms, the impurity species and the atomic size. (C) 2015 Elsevier B.V. All rights reserved.