Influence of Severe Plastic Deformation on Mechanical Properties of an AA5024 Alloy

Abstract:

The paper reports on the effect of severe plastic deformation on mechanical properties of an Al-4.57Mg-0.35Mn-0.2Sc-0.09Zr (in wt. pct.) alloy processed by equal channel angular pressing followed by cold rolling (CR). The sheets of the 5024 alloy with coarse grained (CG) structure exhibited a yield stress (YS) near 410 MPa and an ultimate tensile strength (UTS) of 480 MPa, while the YS and UTS of this material with ultrafine-grained (UFG) structure increased to 530 and 560 MPa, respectively. On the other hand, the elongation to failure decreased by a factor of 2 and 4 after CR and CR following ECAP, respectively. It was shown that dislocation strengthening attributed to extensive CR plays a major role in achieving high strength of this alloy. Besides these macroscopic characteristics, jerky flow caused by the Portevin-Le Chatelier (PLC) instability of plastic deformation was examined. The formation of UFG structure results in a transition from mixed type A+B to pure type B PLC serrations. No such effect on the serrations type was observed after CR.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 1317-1322
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.1317
• Online since: November 2016
• Authors: Anna Mogucheva*, Diana Yuzbekova, Tatiana Lebedkina, Mikhail Lebyodkin, Rustam Kaibyshev
• Keywords: Aluminum Alloy, Cold Rolling, Equal-Channel Angular Pressing (ECAP), Mechanical Properties, PLC Effect, Severe Plastic Deformation (SPD), Strain Hardening

References

[1] R.Z. Valiev and T.G. Langdon, Principles of equal-channel angular pressing as a processing tool for grain refinement Prog. Mater. Sci., 2006, vol. 51, pp.881-981.

DOI: 10.1016/j.pmatsci.2006.02.003

[2] Y. Saito et al., Improvement in the r-Value of Aluminum Strip by a Continuous Shear Deformation Process, Scr. Mater. 42 (2000) 1139-1144.

DOI: 10.1016/s1359-6462(00)00349-3

[3] I. Nikulin, R. Kaibyshev, T. Sakai, Superplasticity in a 7055 aluminum alloy processed by ECAE and subsequent isothermal rolling, Mater. Sci. Eng. A 407 (2005) 62-70.

DOI: 10.1016/j.msea.2005.06.014

[4] A. Dubyna, A. Mogucheva, R. Kaibyshev, Effect of extensive rolling on mechanical properties of an Al-Mg-Sc alloy, Published Online: 4 SEP 2012. DOI: 10. 1002/9781118495292. Copyright © 2012 by The Minerals, Metals, & Materials Society. (2012).

DOI: 10.1007/978-3-319-48761-8_282

[5] A. Mogucheva, E. Babich, B. Ovsyannikov, R. Kaibyshev, Microstructural evolution in a 5024 aluminum alloy processed by ECAP with and without back pressure, Mater. Sci. Eng. A 560 (2013) 178-192.

DOI: 10.1016/j.msea.2012.09.054

[6] A. Mogucheva, R. Kaibyshev, Effect of Intense Plastic Straining and Subsequent Heat Treatment on Mechanical Properties of an Al-Li-Mg-Sc-Zr Alloy, Adv. Mater. Res. 89-91 (2010) 389-394.

DOI: 10.4028/www.scientific.net/amr.89-91.389

[7] I. Nikulin, A. Kipelova, S. Malopheyev, R. Kaibyshev, Effect of second phase particles on grain refinement during equal-channel angular pressing of an Al-Mg-Mn alloy, Acta Mater. 60 (2012) 487-497.

DOI: 10.1016/j.actamat.2011.10.023

[8] J.K. Mackenzie, Second paper on statistics associated with the random disorientation of cubes, Biometrika, 45 (1958) 229-240.

DOI: 10.1093/biomet/45.1-2.229

[9] M. Wagenhofer, M. Erickson-Natishan, R.W. Armstrong, F.J. Zerilli, Influence of strain rate and grain size on yield and serrated flow in commercial Al-Mg alloy 5086, Scripta Mater., 41 (1999) 1177–84.

DOI: 10.1016/s1359-6462(99)00265-1

[10] A. Portevin, F. LeChatelier, Sur un phenomene observe lors de l'essai de traction d'alliages en cours de transformation, Compt. Rend. Acad. Sci. Paris. 176 (1923) 507-510.

[11] H. Aboulfadl, J. Deges, P. Choi and D. Raabe, Dynamic strain aging studied at the atomic scale, Acta Mater. 86 (2015) 34-42.

DOI: 10.1016/j.actamat.2014.12.028

[12] I.V. Shashkov, M.A. Lebyodkin, T.A. Lebedkina, Multiscale study of acoustic emission during smooth and jerky flow in an AlMg alloy, Acta Mater. 60 (2012) 6842-6850.

DOI: 10.1016/j.actamat.2012.08.058

[13] D.А. Zhemchuzhnikova, M.A. Lebyodkin, T.A. Lebedkina, R.O. Kaibyshev, Unusual behavior of the Portevin–Le Chatelier effect in an AlMg alloy containing precipitates, Mater. Sci. Eng. A 639 (2015) 37-41.

DOI: 10.1016/j.msea.2015.04.094

[14] S. Malopheyev, R. Kaibyshev, Strengthening mechanisms in a Zr-modified 5083 alloy deformed to high strains, Mater. Sci. Eng. A 620 (2014) 246–252.

DOI: 10.1016/j.msea.2014.10.030

[15] P. Fernandez-Zelaia, B.S. Adair, V.M. Barker, S.D. Antolovich, The Portevin-Le Chatelier Effect in the Ni-Based Superalloy IN100, Metall. Mater. Trans. A 46 (2015) 5596-5609.

DOI: 10.1007/s11661-015-3126-7