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Dislocation core structure and dynamics in two atomic models of α-zirconium / H.A. Khater in Acta materialia, Vol. 58 N° 8 (Mai 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 2978–2987 Titre : Dislocation core structure and dynamics in two atomic models of α-zirconium Type de document : texte imprimé Auteurs : H.A. Khater, Auteur ; D. J. Bacon, Auteur Année de publication : 2011 Article en page(s) : pp. 2978–2987 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Dislocation  dynamics  Dislocation  structure  Stacking  faults  Molecular  dynamics  simulations  Zirconium Résumé : Properties of basal and first order prism plane dislocations with Burgers vector 1/3 〈View the MathML source〉 in α-Zr have been investigated by computer simulation. Results for a recent interatomic potential (MA07) are assessed and compared with an older one (AWB95). The elastic constants have been calculated with the inner relaxations allowed for and the energy and vector of metastable stacking faults have been determined and compared with published ab initio estimates. The core of the screw dislocation spreads principally in the prism plane in the MA07 model, in contrast to basal plane dissociation in the AWB95 model, and the prism-to-basal ratio of the Peierls stress for the screw is 0.28 with the MA07 model, compared with 3.31 with the AWB95 model. Simulation of the dynamics of dislocation motion under applied stress reveal how the drag coefficient varies with slip system and temperature. The results for the MA07 model are consistent with the known slip geometry of Zr, suggesting that it offers significant advantages for large-scale atomic simulation of dislocation behaviour. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S135964541000042X [article] Dislocation core structure and dynamics in two atomic models of α-zirconium [texte imprimé] / H.A. Khater, Auteur ; D. J. Bacon, Auteur . - 2011 . - pp. 2978–2987. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 2978–2987 Mots-clés : Dislocation  dynamics  Dislocation  structure  Stacking  faults  Molecular  dynamics  simulations  Zirconium Résumé : Properties of basal and first order prism plane dislocations with Burgers vector 1/3 〈View the MathML source〉 in α-Zr have been investigated by computer simulation. Results for a recent interatomic potential (MA07) are assessed and compared with an older one (AWB95). The elastic constants have been calculated with the inner relaxations allowed for and the energy and vector of metastable stacking faults have been determined and compared with published ab initio estimates. The core of the screw dislocation spreads principally in the prism plane in the MA07 model, in contrast to basal plane dissociation in the AWB95 model, and the prism-to-basal ratio of the Peierls stress for the screw is 0.28 with the MA07 model, compared with 3.31 with the AWB95 model. Simulation of the dynamics of dislocation motion under applied stress reveal how the drag coefficient varies with slip system and temperature. The results for the MA07 model are consistent with the known slip geometry of Zr, suggesting that it offers significant advantages for large-scale atomic simulation of dislocation behaviour. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S135964541000042X