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Study of Geometrically Necessary Dislocations of a Partially Recrystallized Aluminum Alloy Using 2D EBSD

Published online by Cambridge University Press:  10 April 2019

Majid Seyed Salehi Open the ORCID record for Majid Seyed Salehi [Opens in a new window] ,
Nozar Anjabin  and
Hyoung S. Kim
Majid Seyed Salehi*
Affiliation:
Department of Materials Science and Engineering, K. N. Toosi University of Technology, P.O. Box: 15875-4416, Tehran, Iran
Nozar Anjabin
Affiliation:
Department of Materials Science and Engineering, School of Engineering, Shiraz University, Zand Ave., Shiraz, Iran
Hyoung S. Kim
Affiliation:
Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
*
*Author for correspondence: Majid Seyed Salehi, E-mail: seyedsalehi@kntu.ac.ir
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Abstract

During recrystallization, the growth of fresh grains initiated within a deformed microstructure causes dramatic changes in the dislocation structure and density of a heavily deformed matrix. In this paper, the microstructure of a cold rolled and partially recrystallized Al-Mg alloy (AA5052) was studied via electron backscattered diffraction (EBSD) analysis. The structure and density of the geometrically necessary dislocations (GNDs) were predicted using a combination of continuum mechanics and dislocation theory. Accordingly, the Nye dislocation tensor, which determines the GND structure, was estimated by calculation of the lattice curvature. To do so, five components of the Nye dislocation tensor were directly calculated from the local orientation of surface points of the specimen, which was determined by two-dimensional EBSD. The remaining components of GNDs were determined by minimizing a normalized Hamiltonian equation based on dislocation energy. The results show the elimination of low angle boundaries, lattice curvature, and GNDs in recrystallized regions and the formation of low angle boundaries with orientation discontinuities in deformed grains, which may be due to static recovery.

Keywords

Electron backscatter diffractiongeometrically necessary dislocationsNye dislocation tensorpartially recrystallization
Type
Materials Applications
Information
Microscopy and Microanalysis , Volume 25 , Issue 3 , June 2019 , pp. 656 - 663
Copyright
Copyright © Microscopy Society of America 2019 

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