A strain gradient crystal plasticity analysis of grain size effects in polycrystals

Ulrik Borg

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The influence of grain size on yield and flow stress in polycrystalline metals is analyzed using a strain gradient crystal plasticity theory with an internal material length scale. The numerical solutions are obtained with them finite element method considering a polycrystal modeled by 40 individually oriented grains, in a unit cell, each having three planar slip systems. An energy potential that penalizes crystallographic slip at grain boundaries is included in the analyzes. The polycrystal is subjected to plane strain tension for various grain sizes and higher order boundary conditions at the grain boundaries. An increase in flow stress with decreasing grain size, d, was obtained on the form d(-n), with n in the range 0.82 to 1.25 at initial yield and in the range 0.77 to 1.09 after 0.1 logarithmic strain.
Original languageEnglish
JournalEuropean Journal of Mechanics A - Solids
Volume26
Issue number2
Pages (from-to)313-324
ISSN0997-7538
DOIs
Publication statusPublished - 2007

Keywords

  • strain gradient plasticity
  • crystal plasticity
  • grain size effects

Cite this