Strain-path effects on the evolution of microstructure and texture during the severe-plastic deformation of aluminum

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Authors
Salem, A.A.
Langdon, T.G.
McNelley, T.R.
Kalidindi, S.R.
Semlatin, S.L.
Subjects
Advisors
Date of Issue
2006
Date
Publisher
Springer
Language
Abstract
Microstructure and texture evolution during the severe-plastic deformation (SPD) of unalloyed aluminum were investigated to establish the effect of processing route and purity level on grain refinement and subgrain formation. Two lots of aluminum with different purity levels (99.998 pct Al and 99 pct Al) were subjected to large plastic strains at room temperature via four different deformation processes: equal-channel angular extrusion (ECAE), sheet rolling, conventional conical-die extrusion, and uniaxial compression. Following deformation, microstructures and textures were determined using orientation-imaging microscopy. In commercial-purity aluminum, the various deformation routes yielded an ultrafine microstructure with a ;1.5-mm grain size, deduced to have been formed via a dynamic-recovery mechanism. For high-purity aluminum, on the other hand, the minimum grain size produced after the various routes was ;20 mm; the high fraction of high-angle grain boundaries (HAGBs) and the absence of subgrains/deformation bands in the final microstructure suggested the occurrence of discontinuous static recrystallization following the large plastic deformation at room temperature. The microstructure differences were underscored by the mechanical properties following four ECAE passes. The yield strength of commercial-purity aluminum quadrupled, whereas the high-purity aluminum showed only a minor increase relative to the annealed condition.
Type
Article
Description
The article of record as published may be found at http://dx.doi.org/10.1007/BF02586120
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Air Force
National Science Foundation
Air Force Office of Scientific Research
Funder
Contract no. F33615-03-D-5801 (AF)
Grant no. DMR-02343331 (NSF)
FA9550-04-1-0018 (AFOSR)
Format
13 p.
Citation
A.A. Salem, T.G. Langdon, T.R. McNelley, S.R. Kalidindi, S.L. Semiatin, "Strain-path effects on the evolution of microstructure and texture during the severe-plastic deformation of aluminum," Metallurgical and Materials Transactions A v.37A, (2006), pp. 2879-2891.
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Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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