Modeling and simulation on ultrafine-graining based on multiscale crystal plasticity considering dislocation patterning

Y. Aoyagi, R. Kobayashi, Y. Kaji, K. Shizawa

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20 Citations (Scopus)

Abstract

Ultrafine-grained metals whose grain size is less than one micron have attracted interest as high strength materials. However, a mechanism of ultrafine-graining based on evolution of dislocation structures has not been clarified. In this study, we derive reaction-diffusion equations for dislocation patterning of dislocation cell structures and subgrains. In order to express the generation of dislocation pattern responding to deformation progress, information of slip rate and stress and effect of interactions between slip systems on formation of cell structures are introduced into the reaction rate coefficients of reaction-diffusion equations. Moreover, we propose a multiscale crystal plasticity model based on dislocation patterning. Then we carry out pseudo-three-dimensional FE-FD hybrid simulation for severe compression of FCC polycrystal using the present model. Some processes of ultrafine-graining, i.e., generation of dislocation cell structures, subgrains, dense dislocation walls and lamella subdivisions with high angle boundaries are numerically reproduced, and we investigate the effect of dislocation behavior on the processes of ultrafine-graining.

Original languageEnglish
Pages (from-to)13-28
Number of pages16
JournalInternational Journal of Plasticity
Volume47
DOIs
Publication statusPublished - 2013 Aug 1

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Keywords

  • A. Dislocations
  • A. Microstructures
  • B. Crystal plasticity
  • B. Metallic material
  • Ultrafine-grained metal

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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