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Polycrystalline iron under compression: Plasticity and phase transitions

Research output: Contribution to journalArticle

  • Nina Gunkelmann
  • Eduardo M. Bringa
  • Keonwook Kang
  • Graeme J. Ackland
  • Carlos J. Ruestes
  • Herbert M. Urbassek

Related Edinburgh Organisations

Original languageEnglish
Article number144111
Number of pages11
JournalPhysical Review B: Condensed Matter and Materials Physics
Volume86
Issue number14
DOIs
Publication statusPublished - 16 Oct 2012

Abstract

Iron undergoes a bcc to close-packed structural phase transition under pressure, at around 13 GPa, as shown by diamond anvil and shock experiments. Atomistic simulations have been able to provide insights into the transition, but without any plasticity occurring before the phase change, in single crystals, defective single crystals, or polycrystals. However, experiments in polycrystals do show clear evidence for plasticity. Here we study homogeneous uniaxial compression of polycrystalline Fe using several interatomic potentials: three embedded-atom-model potentials and one modified embedded-atom-model potential. We analyze grain-boundary rotation and dislocation activity, and find that the amount of dislocation activity as a function of strain depends greatly on the potential used. This variation can be explained in terms of the dislocation properties, calculated in this work for each of these potentials.

    Research areas

  • MOLECULAR-DYNAMICS SIMULATIONS, AB-INITIO, NANOCRYSTALLINE MATERIALS, INTERATOMIC POTENTIALS, SCREW DISLOCATIONS, CORE STRUCTURE, ALPHA-IRON, METALS, BCC, CRYSTALS

ID: 11320763