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Evolution of microstructure and hardness in pure Al by twist extrusion

Orlov, Dmitry; Beygelzimer, Yan; Synkov, Sergey; Varyukhin, Viktor and Horita, Zenji (2008) In Materials Transactions 49(1). p.2-6
Abstract

High purity Al (99.99%) is subjected to severe plastic deformation (SPD) at room temperature using a process of twist extrusion (TE). The microstructure evolution and the related change in microhardness are examined with respect to imposed strain. It is shown that subgrains develop after the first TE pass with a size of ∼1.6 μm and this size remains essentially the same for further application of TE passes. However, dislocations become less visible within grains and grain boundaries become straight and well-defined with misorientation angle higher as the imposed strain is increased. The hardness increases with imposed strain when the magnitude of the strain is small. However, as the imposed strain is large, the hardness decreases due to... (More)

High purity Al (99.99%) is subjected to severe plastic deformation (SPD) at room temperature using a process of twist extrusion (TE). The microstructure evolution and the related change in microhardness are examined with respect to imposed strain. It is shown that subgrains develop after the first TE pass with a size of ∼1.6 μm and this size remains essentially the same for further application of TE passes. However, dislocations become less visible within grains and grain boundaries become straight and well-defined with misorientation angle higher as the imposed strain is increased. The hardness increases with imposed strain when the magnitude of the strain is small. However, as the imposed strain is large, the hardness decreases due to a reduction of dislocations within grains. It is confirmed that these results obtained with TE are consistent with those reported using equal-channel angular pressing (ECAP) and high pressure torsion (HPT), indicating that the microstructural change and the variation of related mechanical properties with straining observed in pure Al are not affected significantly by the methods of SPD processing. © 2008 The Japan Institute of Metals.

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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aluminum, Hardness, Severe plastic deformation, Transmission electron microscopy, Twist extrusion
in
Materials Transactions
volume
49
issue
1
pages
5 pages
publisher
Japan Institute of Metals (JIM)
external identifiers
  • scopus:39549106902
ISSN
1345-9678
DOI
10.2320/matertrans.ME200724
language
English
LU publication?
no
id
30014c90-ea7a-46b0-b463-67d46576b5d5
date added to LUP
2016-06-20 15:43:00
date last changed
2017-09-10 05:07:10
@article{30014c90-ea7a-46b0-b463-67d46576b5d5,
  abstract     = {<p>High purity Al (99.99%) is subjected to severe plastic deformation (SPD) at room temperature using a process of twist extrusion (TE). The microstructure evolution and the related change in microhardness are examined with respect to imposed strain. It is shown that subgrains develop after the first TE pass with a size of ∼1.6 μm and this size remains essentially the same for further application of TE passes. However, dislocations become less visible within grains and grain boundaries become straight and well-defined with misorientation angle higher as the imposed strain is increased. The hardness increases with imposed strain when the magnitude of the strain is small. However, as the imposed strain is large, the hardness decreases due to a reduction of dislocations within grains. It is confirmed that these results obtained with TE are consistent with those reported using equal-channel angular pressing (ECAP) and high pressure torsion (HPT), indicating that the microstructural change and the variation of related mechanical properties with straining observed in pure Al are not affected significantly by the methods of SPD processing. © 2008 The Japan Institute of Metals.</p>},
  author       = {Orlov, Dmitry and Beygelzimer, Yan and Synkov, Sergey and Varyukhin, Viktor and Horita, Zenji},
  issn         = {1345-9678},
  keyword      = {Aluminum,Hardness,Severe plastic deformation,Transmission electron microscopy,Twist extrusion},
  language     = {eng},
  number       = {1},
  pages        = {2--6},
  publisher    = {Japan Institute of Metals (JIM)},
  series       = {Materials Transactions},
  title        = {Evolution of microstructure and hardness in pure Al by twist extrusion},
  url          = {http://dx.doi.org/10.2320/matertrans.ME200724},
  volume       = {49},
  year         = {2008},
}