The University of Southampton
University of Southampton Institutional Repository

Effect of heat treatments on the microstructures and tensile properties of an ultrafine-grained Al-Zn-Mg alloy processed by ECAP

Effect of heat treatments on the microstructures and tensile properties of an ultrafine-grained Al-Zn-Mg alloy processed by ECAP
Effect of heat treatments on the microstructures and tensile properties of an ultrafine-grained Al-Zn-Mg alloy processed by ECAP
An investigation was conducted to determine the microstructures and tensile properties of an ultrafine-grained (UFG) Al-Zn-Mg alloy which was processed by equal-channel angular pressing (ECAP) for 1 and 4 passes at 423 K followed by heat treatments at 393 K for 5 or 20 h. Prior to ECAP, the Al alloy was in a T6 condition (solid solution treatment and peak aging) such that the precipitates introduced were able to hinder dislocation motions and enhance the grain refinement during ECAP. The results show that the yield strengths are enhanced but the ductilities are reduced after processing by ECAP for 1 and 4 passes but heat treatments at 393 K for up to 20 h are advantageous for improving both the yield strengths and the ductilities of the ECAP-processed alloy. The strength also increases with increasing holding time at 393 K from 5 to 20 h. A post-ECAP heat treatment improves the yield strength for the alloy after 1 pass of ECAP more effectively than after 4 passes. After post-ECAP heat treatments, precipitates containing GP zones, η′, η, T and E are distributed within the Al matrix. Large numbers of uniformly distributed nano-scale fine precipitates of η′, combined with ultra-fine grains and a high density of dislocations, contribute to produce an optimized balance between strength and ductility after ECAP for 1 pass and heat treatment at 393 K for 20 h.
0925-8388
567-574
Afifi, Mohamed A.
1becb81a-3778-40ea-bb51-162e3535524d
Wang, Ying Chun
5c067a6f-de5d-4fcb-9b0d-80a42c3634b0
Pereira, Pedro H.R.
9ee129fd-0e06-482d-990c-971aaf83b1d0
Huang, Yi
9f4df815-51c1-4ee8-ad63-a92bf997103e
Wang, Yangwei
13b61d05-0bce-42db-a559-eb9b1982c0a6
Cheng, Xingwang
fc2261b8-46f6-4ca9-ab11-b1ef5bee8e70
Li, Shukui
ffd4a747-b445-4dbe-8122-65b62a1e0857
Langdon, Terence G.
86e69b4f-e16d-4830-bf8a-5a9c11f0de86
Afifi, Mohamed A.
1becb81a-3778-40ea-bb51-162e3535524d
Wang, Ying Chun
5c067a6f-de5d-4fcb-9b0d-80a42c3634b0
Pereira, Pedro H.R.
9ee129fd-0e06-482d-990c-971aaf83b1d0
Huang, Yi
9f4df815-51c1-4ee8-ad63-a92bf997103e
Wang, Yangwei
13b61d05-0bce-42db-a559-eb9b1982c0a6
Cheng, Xingwang
fc2261b8-46f6-4ca9-ab11-b1ef5bee8e70
Li, Shukui
ffd4a747-b445-4dbe-8122-65b62a1e0857
Langdon, Terence G.
86e69b4f-e16d-4830-bf8a-5a9c11f0de86

Afifi, Mohamed A., Wang, Ying Chun, Pereira, Pedro H.R., Huang, Yi, Wang, Yangwei, Cheng, Xingwang, Li, Shukui and Langdon, Terence G. (2018) Effect of heat treatments on the microstructures and tensile properties of an ultrafine-grained Al-Zn-Mg alloy processed by ECAP. Journal of Alloys and Compounds, 749, 567-574. (doi:10.1016/j.jallcom.2018.03.206).

Record type: Article

Abstract

An investigation was conducted to determine the microstructures and tensile properties of an ultrafine-grained (UFG) Al-Zn-Mg alloy which was processed by equal-channel angular pressing (ECAP) for 1 and 4 passes at 423 K followed by heat treatments at 393 K for 5 or 20 h. Prior to ECAP, the Al alloy was in a T6 condition (solid solution treatment and peak aging) such that the precipitates introduced were able to hinder dislocation motions and enhance the grain refinement during ECAP. The results show that the yield strengths are enhanced but the ductilities are reduced after processing by ECAP for 1 and 4 passes but heat treatments at 393 K for up to 20 h are advantageous for improving both the yield strengths and the ductilities of the ECAP-processed alloy. The strength also increases with increasing holding time at 393 K from 5 to 20 h. A post-ECAP heat treatment improves the yield strength for the alloy after 1 pass of ECAP more effectively than after 4 passes. After post-ECAP heat treatments, precipitates containing GP zones, η′, η, T and E are distributed within the Al matrix. Large numbers of uniformly distributed nano-scale fine precipitates of η′, combined with ultra-fine grains and a high density of dislocations, contribute to produce an optimized balance between strength and ductility after ECAP for 1 pass and heat treatment at 393 K for 20 h.

Text
Yingchun-JALCOM-March2018 - Accepted Manuscript
Download (1MB)

More information

Accepted/In Press date: 15 March 2018
e-pub ahead of print date: 19 March 2018
Published date: 15 June 2018

Identifiers

Local EPrints ID: 418944
URI: http://eprints.soton.ac.uk/id/eprint/418944
ISSN: 0925-8388
PURE UUID: 09dbf7f0-616f-4824-9219-fde7cdc64632
ORCID for Yi Huang: ORCID iD orcid.org/0000-0001-9259-8123
ORCID for Terence G. Langdon: ORCID iD orcid.org/0000-0003-3541-9250

Catalogue record

Date deposited: 26 Mar 2018 16:30
Last modified: 17 Dec 2019 05:32

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×