We apply a theory of single-crystal plasticity with microstructure to the simulation of the ECAE process. The specific microstructures considered in the simulations are of the sequential lamination type. The size of the microstructure is estimated a posteriori by means of a nonlocal extension of the theory which accounts for dislocation energies. Texture evolution is calculated simply by recourse to Taylor's hypothesis. Calculations concerned with an FCC material (Al-Cu alloy) and 90° ECAE reveal a wealth of information regarding the geometry, size, and texture evolution of subgrain microstructures. The predicted sizes and textures are in good quantitative agreement with the available experimental data. © 2004 Elsevier B.V. All rights reserved.

M S Sivakumar

Department of Applied Mechanics

Dislocations (crystals)

extrusion

Laminating

Textures

Microstructure evolution

NONLOCAL EXTENSION

SUBGRAIN MICROSTRUCTURES

microstructure

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Computer Methods in Applied Mechanics and Engineering

A minimum plastic power principle is proposed for a rigid-viscoplastic crystalline domain subdivided into two sets of lath-shaped regions, called bands. The lattice orientation in each band is assumed uniform and to differ infinitesimally from that in the other band. The proposed minimum principle yields the slip activity in the bands and semi-analytical expressions for the misorientation axis and orientation of band boundaries. These band boundary characteristics are predicted for f.c.c. lattice orientations near the ideal rolling texture components. Surprisingly, it found that the predicted band boundary characteristics closely match those of microstructural features called cell block boundaries reported in the experimental literature, except when the dislocations of activated slip systems are known to interact very strongly. This suggests that except when precluded by strong dislocation interactions, continuum extremum principles may also govern microstructural characteristics. © 2015 Elsevier Ltd. All rights reserved.

Journal of the Mechanics and Physics of Solids

A minimum principle for microstructuring in rigid-viscoplastic crystalline solids

This paper explores a link between a recently proposed macroscopic "smeared" approach and a microscopic/mesoscopic approach of sequential laminate type to model martensitic transformations. In addition, a numerical simulation of the stress-induced martensitic transformation in a single crystal has been performed upon simplification to small deformations. One significant observation in the results of such a simulation is the counter-intuitive change of preferred martensitic plate even under proportional loading conditions. It remains to be seen if it is an artifact of the procedure adopted or the actual shift of active martensitic plate system. A further step toward modeling polycrystal behavior using homogenization with simple bounds has been attempted. Hysteresis results show that there is no clear demarcation of critical stress at which the transformation occurs. This may be critical to the functional fatigue behavior of shape memory materials. © 2007 Elsevier Ltd. All rights reserved.

Nonlinear Analysis: Real World Applications

On smeared and micromechanical approaches to modeling martensitic transformations in SMA

Solid State Phenomena Bulk and Graded Nanometals

Perspective of Nanomaterials Production, by Cyclic Extrusion Compression Method of Exerting Unconventional, Large Plastic Deformations

Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences

The mechanics of deformation–induced subgrain–dislocation structures in metallic crystals at large strains

Materials Science Forum

Investigation of Texture in ECAP Materials Using Neutron Diffraction

A constrained sequential-lamination algorithm for the simulation of sub-grid microstructure in martensitic materials

Materials Science and Engineering: A

Modeling texture and microstructural evolution in the equal channel angular extrusion process

Microstructure evolution in the equal channel angular extrusion process

Journal	Computer Methods in Applied Mechanics and Engineering
ISSN	00457825
Open Access	No