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A model of grain fragmentation based on lattice curvature

Version 2 2024-06-04, 05:22
Version 1 2015-08-20, 15:42
journal contribution
posted on 2024-06-04, 05:22 authored by LS Tóth, Y Estrin, Rimma LapovokRimma Lapovok, C Gu
A new model is proposed that aims to capture within a single modelling frame all the main microstructural features of a severe plastic deformation process. These are: evolution of the grain size distribution, misorientation distribution, crystallographic texture and the strain-hardening of the material. The model is based on the lattice curvature that develops in all deformed grains. The basic assumption is that lattice rotation within an individual grain is impeded near the grain boundaries by the constraining effects of the neighbouring grains, which gives rise to lattice curvature. On that basis, a fragmentation scheme is developed which is integrated in the Taylor viscoplastic polycrystal model. Dislocation density evolution is traced for each grain, which includes the contribution of geometrically necessary dislocations associated with lattice curvature. The model is applied to equal-channel angular pressing. The role of texture development is shown to be an important element in the grain fragmentation process. Results of this modelling give fairly precise predictions of grain size and grain misorientation distribution. The crystallographic textures are well reproduced and the strength of the material is also reliably predicted based on the modelling of dislocation density evolution coupled with texture development.

History

Journal

Acta materialia

Volume

58

Pagination

1782-1794

Location

Oxford, Eng.

ISSN

1359-6454

Language

eng

Publication classification

C Journal article, C1.1 Refereed article in a scholarly journal

Copyright notice

2009, Acta Materialia

Issue

5

Publisher

Elsevier