Influence of grain size and Mg content on the ductility of Al-Mg alloys at low temperatures.

Ultrafine-grained (UFG) binary Al-xMg (x=1, 5 and 7 wt %) alloys were processed by equal channel angular pressing (ECAP) at room temperature via route Bccombined with inter-pass annealing. The effects of Mg content, grain size and strain rate on mechanical properties and dynamic strain aging (DSA) behaviour of the Al-Mg alloys upon tensile testing at room temperature were studied. An increase in Mg content from 5 to 7 wt % leads to a pronounced increase in strength and uniform elongation in both the as-homogenized and as-ECAP Al-Mg alloys. Thereby, the Al-7Mg alloy, either prior to or after ECAP processing, possess significantly higher strength and comparable or even higher uniform elongation than the more dilute Al-Mg alloys. However, the as-ECAP Al-Mg alloys exhibit significantly higher strength but little work hardening and hence rather limited uniform elongation. In general, decreasing grain size leads to significant increase in strength while dramatic decrease in ductility. Moreover, DSA serration amplitudes increase with reducing grain size in the micrometer range. However, the UFG Al-Mg alloys exhibit much less DSA effect than the micrometer scaled grain size counterparts, i.e. probably due to the high dislocation densities and special grain boundary features in the UFG materials. Also, the Al-Mg alloys, especially those with a UFG structure, exhibit higher strength and ductility at lower strain rate than at higher strain rate, due mainly to enhanced DSA effect and hence work hardening at a lower strain rate.

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Effect of Mg content on the minimum grain size of Al–Mg alloys obtained by friction stir processing

Scripta Materialia ◽

10.1016/j.scriptamat.2010.10.033 ◽

2011 ◽

Vol 64 (4) ◽

pp. 355-358 ◽

Cited By ~ 56

Author(s):

Taiki Morishige ◽

Tomotake Hirata ◽

Tokuteru Uesugi ◽

Yorinobu Takigawa ◽

Masato Tsujikawa ◽

...

Keyword(s):

Grain Size ◽

Friction Stir Processing ◽

Mg Alloys ◽

Friction Stir ◽

Mg Content ◽

Al Mg Alloys

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Influence of temperature and strain rate of tensile testing and grain size on yield point elongation in Al-Mg alloys.

Journal of Japan Institute of Light Metals ◽

10.2464/jilm.48.312 ◽

1998 ◽

Vol 48 (7) ◽

pp. 312-316 ◽

Cited By ~ 1

Author(s):

Atsuya INAGAKI ◽

Toshio KOMATSUBARA ◽

Hirosuke INAGAKI

Keyword(s):

Grain Size ◽

Strain Rate ◽

Yield Point ◽

Tensile Testing ◽

Mg Alloys ◽

Influence Of Temperature ◽

Yield Point Elongation ◽

Al Mg Alloys

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Effects of high Mg content and processing parameters on Portevin-Le Chatelier and negative strain rate sensitivity effects in Al–Mg alloys

Materials Science and Engineering A ◽

10.1016/j.msea.2020.139151 ◽

2020 ◽

Vol 779 ◽

pp. 139151 ◽

Cited By ~ 3

Author(s):

Chang-Hee Cho ◽

Hyeon-Woo Son ◽

Jae-Cheol Lee ◽

Kwang-Tae Son ◽

Ji-Woon Lee ◽

...

Keyword(s):

Strain Rate ◽

Strain Rate Sensitivity ◽

Rate Sensitivity ◽

Processing Parameters ◽

Mg Alloys ◽

Negative Strain Rate Sensitivity ◽

Mg Content ◽

Al Mg Alloys

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Effect of Deformation Route and Sc and Zr Addition on Ultra-Fine Grain Formation and Superplasticity in Al-Mg Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.519-521.847 ◽

2006 ◽

Vol 519-521 ◽

pp. 847-852

Author(s):

Suk Bong Kang ◽

Jae Woon Kim ◽

Hyoung Wook Kim

Keyword(s):

Grain Size ◽

Strain Rate ◽

Deformation Process ◽

Mg Alloys ◽

Fine Grained ◽

Loading Direction ◽

Zr Addition ◽

Average Grain Size ◽

Multiple Deformation ◽

Al Mg Alloys

Recently the method for obtaining ultra-fine grained metallic materials has developed using severe plastic deformation (SPD), such as equal channel angular pressing (ECAP), accumulative roll bonding (ARB), torsion straining, and warm multiple deformation (WMD) etc. In order to enhance thermal stability of ultra-fine grained aluminum alloys manufactured by SPD process, the addition of Sc and Zr elements has been considered to devise fine Al3Sc, Al3Zr and Al3(Scx Zr1-x) precipitates for inhibiting the grain growth. In this study, the microstructure evolution has been investigated in Al-Mg alloys with and without Sc and Zr addition during the warm multiple deformation process. In addition Al-Mg alloys were compressed at a strain rate of 10-1 sec-1 by two different routes, that is, route A and route B. Route A is to rotate the specimen throughout 90o around the vertical axis of loading direction at every pass. Route B is to rotate the specimen throughout 90o around the parallel axis of loading direction and then rotate it again as route A. The specimen deformed by route B had finer grain size and more uniform distribution of grains than those deformed by route A. When the warm multiple deformation process repeated up to 8 passes at 673 K, the specimen consisted of ultra-fine grained structure with the average grain size less than 3 μm. The superplastic behavior can also be observed at the high strain rate and low temperature regime.

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