Memorias de investigación
Artículos en revistas:
Assessment of interatomic potentials for atomistic analysis of static and dynamic properties of screw dislocations in W
Año:2013
Áreas de investigación
  • Ingenierías
Datos
Descripción
Screw dislocations in bcc metals display non-planar cores at zero temperature which result in high lattice friction and thermally-activated strain rate behavior. In bcc W, electronic structure molecular statics calculations reveal a compact, non-degenerate core with an associated Peierls stress between 1.7 and 2.8 GPa. However, a full picture of the dynamic behavior of dislocations can only be gained by using more efficient atomistic simulations based on semiempirical interatomic potentials. In this paper we assess the suitability of five different potentials in terms of static properties relevant to screw dislocations in pure W. Moreover, we perform molecular dynamics simulations of stress-assisted glide using all five potentials to study the dynamic behavior of screw dislocations under shear stress. Dislocations are seen to display thermally-activated motion in most of the applied stress range, with a gradual transition to a viscous damping regime at high stresses. We find that one potential predicts a core transformation from compact to dissociated at finite temperature that affects the energetics of kink-pair production and impacts the mechanism of motion. We conclude that a modified embedded-atom potential achieves the best compromise in terms of static and dynamic screw dislocation properties, although at an expense of about ten-fold compared to central potentials. (Some figures may appea
Internacional
Si
JCR del ISI
Si
Título de la revista
JOURNAL OF PHYSICS-CONDENSED MATTER
ISSN
0953-8984
Factor de impacto JCR
2,546
Información de impacto
Volumen
25
DOI
10.1088/0953-8984/25/8/085702
Número de revista
8
Desde la página
0
Hasta la página
11
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SIN MES
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Participantes
  • Autor: David Cereceda Señas UPM
  • Autor: Jose Manuel Perlado Martin UPM
  • Autor: a. stukowski
  • Autor: m. r. gilbert
  • Autor: s. queyreau
  • Autor: lisa ventelon
  • Autor: m-c marinica
  • Autor: j. marian
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Fusión Nuclear Inercial y Tecnología de fusión
  • Centro o Instituto I+D+i: Instituto de Fusión Nuclear
  • Departamento: Ingeniería Nuclear