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The precipitation behavior of a pretwinned Mg–6Al–1Zn alloy and the effect on subsequent deformation

Published online by Cambridge University Press:  12 September 2014

Yin Zhang
Affiliation:
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, People's Republic of China; and National Engineering Research Center for Mg Alloys, Chongqing University, Chongqing 400044, People's Republic of China
Tianmo Liu*
Affiliation:
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, People's Republic of China; and National Engineering Research Center for Mg Alloys, Chongqing University, Chongqing 400044, People's Republic of China
Xuezheng Ding
Affiliation:
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, People's Republic of China; and National Engineering Research Center for Mg Alloys, Chongqing University, Chongqing 400044, People's Republic of China
Shun Xu
Affiliation:
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, People's Republic of China; and National Engineering Research Center for Mg Alloys, Chongqing University, Chongqing 400044, People's Republic of China
Jiejun He
Affiliation:
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, People's Republic of China; and National Engineering Research Center for Mg Alloys, Chongqing University, Chongqing 400044, People's Republic of China
Hongbing Chen
Affiliation:
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, People's Republic of China; and National Engineering Research Center for Mg Alloys, Chongqing University, Chongqing 400044, People's Republic of China
Fusheng Pan
Affiliation:
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, People's Republic of China; and National Engineering Research Center for Mg Alloys, Chongqing University, Chongqing 400044, People's Republic of China
Liwei Lu*
Affiliation:
College of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China
*
a)Address all correspondence to these authors. e-mail: tmliu@cqu.edu.cn
b)e-mail: llwcqu@163.com
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Abstract

In this study, the precipitation behavior of the pretwinned extruded Mg–6Al–1Zn alloy was investigated. It was observed that the precipitates preferentially nucleated at the twin boundaries or within the preexistent twins. This distribution of the precipitates led to the distinguishing influences on subsequent compression and tension process, which were dominated by twinning and detwinning of the preexistent twins, respectively. The compressive yield strength after aging was a little lower than the stress when the precompression was interrupted, which meant that the impeding effect of precipitation on twin expansion was relatively smaller than that of dislocations induced by precompression. However, the tensile yield strength of aged samples was extremely higher than that of non-aged samples as the migration of the twin boundaries during detwinning was considerably hindered because of the preferential precipitation within the preexistent {10-12} twins.

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Articles
Copyright
Copyright © Materials Research Society 2014 

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References

REFERENCES

Máthis, K., Gubicza, J., and Nam, N.H.: Microstructure and mechanical behavior of AZ91 Mg alloy processed by equal channel angular pressing. J. Alloys Compd. 394(1–2), 194 (2005).CrossRefGoogle Scholar
Bohlen, J., Yi, S., Swiostek, J., Letzig, D., Brokmeier, H., and Kainer, K.: Microstructure and texture development during hydrostatic extrusion of magnesium alloy AZ31. Scr. Mater. 53(2), 259 (2005).CrossRefGoogle Scholar
Nie, J.F., Zhu, Y.M., Liu, J.Z., and Fang, X.Y.: Periodic segregation of solute atoms in fully coherent twin boundaries. Science 340(6135), 957 (2013).CrossRefGoogle ScholarPubMed
Robson, J.D., Stanford, N., and Barnett, M.R.: Effect of precipitate shape on slip and twinning in magnesium alloys. Acta Mater. 59(5), 1945 (2011).CrossRefGoogle Scholar
Clark, J.B.: Age hardening in a Mg-9 wt% Al alloy. Acta Metall. 16, 141 (1968).CrossRefGoogle Scholar
Braszczyńska-Malik, K.N.: Discontinuous and continuous precipitation in magnesium–aluminium type alloys. J. Alloys Compd. 477(1–2), 870 (2009).CrossRefGoogle Scholar
Duly, D., Brechet, Y., and Chenal, B.: Macroscopic kinetics of discontinuous precipitation in a Mg-8.5 wt% Al alloy. Acta Mater. 40(9), 2289 (1991).CrossRefGoogle Scholar
Duly, D., Simon, J.P., and Brechet, Y.: On the competition between continuous and discontinuous precipitations in binary Mg-Al alloys. Acta Mater. 43(1), 101 (1995).Google Scholar
Celotto, S.: TEM study of continuous precipitation in Mg-9 wt% Al-1 wt% Zn alloy. Acta Mater. 48, 1775 (2000).CrossRefGoogle Scholar
Zhang, M-X. and Kelly, P.M.: Crystallography of Mg17Al12 precipitates in AZ91D alloy. Scr. Mater. 48, 647 (2003).CrossRefGoogle Scholar
Duly, D., Audier, M., and Brechet, Y.: On the influence of plastic deformation on discontinuous precipitation in Mg-Al. Scr. Metall. 29, 1539 (1993).Google Scholar
Barnett, M.R.: Twinning and the ductility of magnesium alloys Part I: “Tension” twins. Mater. Sci. Eng., A 464(1–2), 1 (2007).CrossRefGoogle Scholar
Barnett, M.: A rationale for the strong dependence of mechanical twinning on grain size. Scr. Mater. 59(7), 696 (2008).CrossRefGoogle Scholar
Pei, Y., Godfrey, A., Jiang, J., Zhang, Y.B., Liu, W., and Liu, Q.: Extension twin variant selection during uniaxial compression of a magnesium alloy. Mater. Sci. Eng., A 550, 138 (2012).CrossRefGoogle Scholar
Wang, Y. and Huang, J.: The role of twinning and untwinning in yielding behavior in hot-extruded Mg–Al–Zn alloy. Acta Mater. 55(3), 897 (2007).CrossRefGoogle Scholar
Gharghouri, M.A., Weatherly, G.C., and Embury, J.D.: The interaction of twins and precipitates in a Mg-7.7 at.% Al alloy. Philos. Mag. A 78(5), 1137 (1998).CrossRefGoogle Scholar
Stanford, N. and Barnett, M.R.: Effect of particles on the formation of deformation twins in a magnesium-based alloy. Mater. Sci. Eng., A 516(1–2), 226 (2009).CrossRefGoogle Scholar
Jain, J., Poole, W.J., Sinclair, C.W., and Gharghouri, M.A.: Reducing the tension–compression yield asymmetry in a Mg–8Al–0.5Zn alloy via precipitation. Scr. Mater. 62(5), 301 (2010).CrossRefGoogle Scholar
Stanford, N., Taylor, A.S., Cizek, P., Siska, F., Ramajayam, M., and Barnett, M.R.: Twinning in magnesium-based lamellar microstructures. Scr. Mater. 67(7–8), 704 (2012).CrossRefGoogle Scholar
Yin, D.L., Wang, J.T., Liu, J.Q., and Zhao, X.: On tension–compression yield asymmetry in an extruded Mg–3Al–1Zn alloy. J. Alloys Compd. 478(1–2), 789 (2009).CrossRefGoogle Scholar
Hong, S-G., Park, S.H., and Lee, C.S.: Role of {10–12} twinning characteristics in the deformation behavior of a polycrystalline magnesium alloy. Acta Mater. 58(18), 5873 (2010).CrossRefGoogle Scholar
Hong, S-G., Park, S.H., and Lee, C.S.: Strain path dependence of {10−12} twinning activity in a polycrystalline magnesium alloy. Scr. Mater. 64(2), 145 (2011).CrossRefGoogle Scholar
Rosalie, J.M., Somekawa, H., Singh, A., and Mukai, T.: The effect of size and distribution of rod-shaped precipitates on the strength and ductility of a Mg–Zn alloy. Mater. Sci. Eng., A 539, 230 (2012).CrossRefGoogle Scholar