TY - GEN

T1 - Fully coupled two-phase composite model for microstructure evolution during non-proportional severe plastic deformation

AU - Shutov, Alexey

N1 - Publisher Copyright: © 2018 Trans Tech Publications, Switzerland

PY - 2018/1/1

Y1 - 2018/1/1

N2 - A fully coupled micro-macro interaction model is proposed for the grain refinement caused by severe plastic deformation of cell-forming metallic materials. The model is a generalization of a previously proposed two-phase composite model suggested for the evolution of dislocation populations corresponding to the interior of the dislocation cells and dislocation cell walls. Just as within the original framework, the evolution of the material microstructure depends on the applied hydrostatic pressure, strain rate, and the loading path. Backstresses are used to define a measure of the strain path change. Thereby, the model can describe the experimentally observed dissolution of dislocation cells and the reduction of dislocation densities occurring shortly after load path changes. The large strain kinematics is accounted for in a geometrically exact manner using the nested split of the deformation gradient tensor, proposed by Lion. Within the extended model, the macroscopic strength of the material depends on the microstructural parameters. In that sense, the new model is fully coupled. It is thermodynamically consistent, objective, and w-invariant under isochoric changes of the reference configuration. A physical interpretation is provided for the nested multiplicative split in terms of the two-phase microstructure composite model.

AB - A fully coupled micro-macro interaction model is proposed for the grain refinement caused by severe plastic deformation of cell-forming metallic materials. The model is a generalization of a previously proposed two-phase composite model suggested for the evolution of dislocation populations corresponding to the interior of the dislocation cells and dislocation cell walls. Just as within the original framework, the evolution of the material microstructure depends on the applied hydrostatic pressure, strain rate, and the loading path. Backstresses are used to define a measure of the strain path change. Thereby, the model can describe the experimentally observed dissolution of dislocation cells and the reduction of dislocation densities occurring shortly after load path changes. The large strain kinematics is accounted for in a geometrically exact manner using the nested split of the deformation gradient tensor, proposed by Lion. Within the extended model, the macroscopic strength of the material depends on the microstructural parameters. In that sense, the new model is fully coupled. It is thermodynamically consistent, objective, and w-invariant under isochoric changes of the reference configuration. A physical interpretation is provided for the nested multiplicative split in terms of the two-phase microstructure composite model.

KW - Dislocation cells

KW - Isotropic

KW - Kinematic hardening

KW - Microstructure evolution

KW - Nested multiplicative split

KW - Non-proportional loading

KW - Severe plastic deformation

UR - http://www.scopus.com/inward/record.url?scp=85052730791&partnerID=8YFLogxK

U2 - 10.4028/www.scientific.net/DDF.385.234

DO - 10.4028/www.scientific.net/DDF.385.234

M3 - Conference contribution

AN - SCOPUS:85052730791

SN - 9783035713459

VL - 385 DDF

SP - 234

EP - 240

BT - Superplasticity in Advanced Materials - ICSAM 2018

PB - Trans Tech Publications Ltd

T2 - 13th International Conference on Superplasticity in Advanced Materials, ICSAM 2018

Y2 - 19 August 2018 through 22 August 2018

ER -