Effects of dislocation boundary spacings and stored energy on boundary migration during recrystallization: A phase-field analysis

Vishal Yadav,Nele Moelans,Yubin Zhang,Dorte Juul Jensen

doi:10.1016/j.actamat.2021.117377

Vishal Yadav, Nele Moelans + Show 2 more

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https://doi.org/10.1016/j.actamat.2021.117377

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Journal: Acta Materialia	Publication Date: Oct 9, 2021
Citations: 12	License type: cc-by

Affiliation: KU Leuven, Technical University of Denmark

Abstract

The local migration of recrystallization boundaries into spatially varying deformation fields which are typical for metals deformed to low and high strains is investigated using quantitative phase-field simulations. It is found that the average migration velocities as well as the local velocities of the recrystallization boundaries critically depend on the spacing between planar geometrically necessary boundaries (GNBs) which are present in the deformation microstructure. Also the morphology of the deformation field reflecting low and high strain deformation cases strongly affect the migrating boundary during recrystallization. Additional simulations were performed as a function of the two critical parameters- stored energy and GNB spacing - independently. Two regimes are found suggesting that these two parameters are closely linked. Previous experimental results are interpreted based on these novel simulation results.

Highlights

During recrystallization of metallic materials, new and almost defect free grains nucleate and grow at the expense of the deformation microstructure
The geometrically necessary boundaries (GNBs) spacing has a significant effect on the migration of the recrystallization boundary in both the X and Y direction
For a given deformation field, the protrusions and retrusions on the migrating boundary are more significant when the boundary is moving in the X direction than when it is moving in the Y direction

Summary

Introduction

During recrystallization of metallic materials, new and almost defect free grains nucleate and grow at the expense of the deformation microstructure. The relationship between recrystallization boundary velocity and driving force is given as: vgb = MgbFs (1). Classical as well as recent experimental studies have documented the presence of significant local variations in the deformed microstructures and irregular motion of the recrystallization boundaries [2,3,4,5,6,7,8]. The results were later substantiated by detailed electron back scattering diffraction (EBSD) studies [9]. In these works, it was suggested that the migration of recrystallization boundaries through a heterogeneous deformation field is complex, and that

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