Memorias de investigación
Research Publications in journals:
Thermally-activated non-Schmid glide of screw dislocations in W using atomistically-informed kinetic Monte Carlo simulations
Year:2015

Research Areas
  • Engineering

Information
Abstract
Thermally-activated 1=2h111i screw dislocation motion is the controlling plastic mechanism at low temperatures in body-centered cubic (bcc) crystals. Dislocation motion proceeds by nucleation and propagation of atomic-sized kink pairs in close-packed planes. The atomistic character of kink pairs can be studied using techniques such as molecular dynamics (MD). However, MD?s natural inability to properly sample thermally-activated processes as well as to capture f110g screw dislocation glide calls for the development of other methods capable of overcoming these limitations. Here we develop a kinetic Monte Carlo (kMC) approach to study single screw dislocation dynamics from room temperature to 0:5Tm and at stresses 0 < r < 0:9rP, where Tm and rP are the melting point and the Peierls stress. The method is entirely parameterized with atomistic simulations using an embedded atom potential for tungsten. To increase the physical fidelity of our simulations, we calculate the deviations from Schmid?s law prescribed by the interatomic potential used and we study single dislocation kinetics using both projections. We calculate dislocation velocities as a function of stress, temperature, and dislocation line length. We find that considering non-Schmid effects has a strong influence on both the magnitude of the velocities and the trajectories followed by the dislocation. We finish by condensing all the calculated data into effective stress and temperature dependent mobilities to be used in more homogenized numerical methods
International
Si
JCR
Si
Title
INTERNATIONAL JOURNAL OF PLASTICITY
ISBN
0749-6419
Impact factor JCR
Impact info
Volume
65
Journal number
From page
108
To page
130
Month
SIN MES
Ranking
Participants
  • Autor: A. Stukowski Institute of Materials Science, Darmstadt University of Technology
  • Autor: David Cereceda Señas UPM
  • Autor: T.D. Swinburne Department of Physics, Imperial College London
  • Autor: J. Marian Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory

Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Fusión Nuclear Inercial y Tecnología de fusión
  • Centro o Instituto I+D+i: Instituto de Fusión Nuclear