Effects of Mn and Cr Additions on the Recrystallization Behavior of Al-Mg-Si-Cu Alloys

Abstract:

Upsetting tests on two newly developed Mn and Cr-containing Al-Mg-Si-Cu alloys with various Mn contents were carried out at a speed of 15 mm/s under upsetting temperature of 450 °C after casting and subsequent homogenization heat treatment using a 300-Tone hydraulic press. STEM experiments revealed that Mn and Cr-containing α-Al (MnCrFe)Si dispersoids formed during homogenization showed a strong pinning effect on dislocations and grain boundaries, which could effectively inhibit recovery and recrystallization during hot deformation in the two alloys. Recrystallization fractions after solution heat treatment following hot deformation were measured by EBSD technique. It was found that the recrystallization fractions of the two alloys were less than 30%, giving rise to lower recrystallization fraction in the alloy with higher amount of Mn, which had higher number density of dispersoids. This implied that the finely distributed α-dispersoids were rather stable against coarsening and they stabilized the microstructure by inhibiting dislocation recovery and recrystallization during elevated temperature exposure. Increasing the content of Mn could increase the number density as well as the aspect ratio of the dispersoids, and more significantly, the effect of retardation on recrystallization were further enhanced.

• Periodical: Materials Science Forum (Volume 877)
• Pages: 172-179
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.877.172
• Online since: November 2016
• Authors: Gong Wang Zhang, Hiromi Nagaumi, Yi Han, Yi Xu, Chad M. Parish, Tong Guang Zhai*
• Keywords: Al-Mg-Si-Cu Aluminium Alloy, Homogenization, Mn Content, Mn-Containing Dispersoids, Recrystallization

References

[1] T. Sheppard, Extrusion of Aluminum Alloys, Kluwer Academic Publishers, Dordrecht, The Netherlands, (1999).

[2] E. Nes, Effect of a fine particle dispersion on heterogeneous recrystallization, Acta Metal. 24 (1976) 391-398.

DOI: 10.1016/0001-6160(76)90059-6

[3] Y.J. Li, L. Arnberg, Quantitative study on the precipitation behavior of dispersoids in DC-cast AA3003 alloy during heating and homogenization, Acta Mater. 51 (2003) 3415-3428.

DOI: 10.1016/s1359-6454(03)00160-5

[4] F. Gatto, G. Camona, M. Conserva, P. Fiorini, Deformation structures and recrystallization behaviour of Al-Mn 1. 04% alloy, Mater. Sci. Eng. 3 (1968/69) 56-61.

DOI: 10.1016/0025-5416(68)90032-3

[5] A.R. Eivani, H. Ahmed, J. Zhou, J. Duszczyk, An experimental and theoretical investigation of the formation of Zr-containing dispersoids in Al-4. 5Zn-1Mg aluminum alloy, Mater. Sci. Eng. A 527 (2010) 2418-2430.

DOI: 10.1016/j.msea.2010.01.012

[6] L.M. Wu, W.H. Wang, Y.F. Hsu, S. Trong, Effects of homogenization treatment on recrystallization behavior and dispersoid distribution in an Al- Zn-Mg-Sc-Zr alloy, J. Alloys. Compounds, 456 (2008) 163-169.

DOI: 10.1016/j.jallcom.2007.02.054

[7] B. Morere, C. Maurice, R. Shahani, J. Driver, The influence of Al3Zr dispersoids on the recrystallization of hot-deformed AA 7010 alloys, Metall. Mater. Trans. A 32A (2001) 625-632.

DOI: 10.1007/s11661-001-0079-9

[8] J.D. Robson, Optimizing the homogenization of zirconium containing commercial aluminium alloys using a novel process model, Mater. Sci. Eng. A 338 (2002) 219-229.

DOI: 10.1016/s0921-5093(02)00061-8

[9] A.R. Eivani, PhD Thesis, Delft, The Netherlands, June (2010).

[10] L. Lodgaard, N. Ryum, Precipitation of dispersoids containing Mn and/or Cr in Al-Mg-Si alloys, Mater. Sci. Eng. A 283 (2000) 144-152.

DOI: 10.1016/s0921-5093(00)00734-6

[11] L. Lodgaard, N. Ryum, Precipitation of chromium containing dispersoids in Al-Mg-Si alloys, Mater. Sci. Technol. 16 (2000) 599-604.

DOI: 10.1179/026708300101508315

[12] R.A. Jeniski, JR., B. Thanaboonsombut, T.H. Sanders, JR., The Effect of Iron and Manganese on the Recrystallization Behavior of Hot-Rolled and Solution-Heat-Treated Aluminum Alloy 6013, Metall. Mater. Trans. A 27A (1996) 19-27.

DOI: 10.1007/bf02647743

[13] R. Hu, T. Ogura, H. Tezuka, T. Sato, Q. Liu, Dispersoid Formation and Recrystallization Behavior in an Al-Mg-Si-Mn Alloy, J. Mater. Sci. Technol. 26 (3) (2010) 237-243.

DOI: 10.1016/s1005-0302(10)60040-0

[14] D.H. Lee, J.H. Park, S.W. Nam, Enhancement of mechanical properties of Al-Mg-Si alloys by means of manganese dispersoids, Mater. Sci. Technol. 15 (1999) 450-455.

DOI: 10.1179/026708399101505923

[15] P.V. Raymond, J.W. Martin, The influence of dispersoids on fatigue crack propagation in Al-Mg-Si alloy, Z. Metallkde 70 (1979) 80-84.

DOI: 10.1515/ijmr-1979-700203

[16] S. Gourdet, F. Montheillet, Experimental study of the recrystallization mechanism during hot deformation of aluminium, Mater. Sci. Eng. A 283 (2000) 274-288.

DOI: 10.1016/s0921-5093(00)00733-4

[17] H.J. McQueen, W. Blum, Dynamic recovery: sufficient mechanism in the hot deformation of Al (< 99. 99), Mater. Sci. Eng. A 290 (2000) 95-107.

DOI: 10.1016/s0921-5093(00)00933-3

[18] H.J. Humphreys, M. Hatherly, Recrystallization and Related Annealing Phenomena, second ed., Elsevier, Oxford, (2004).

[19] H. Zhang, L. Li, D. Yuan, D. Peng, Hot deformation behavior of the new Al–Mg–Si–Cu aluminum alloy during compression at elevated temperatures, Mater. Charact. 58 (2007) 168-173.

DOI: 10.1016/j.matchar.2006.04.012

[20] H.E. Hu, L. Zhen, L. Yang, W.Z. Shao, B.Y. Zhang, Deformation behavior and microstructure evolution of 7050 aluminum alloy during high temperature deformation, Mater. Sci. Eng. A 488 (2008) 64-71.

DOI: 10.1016/j.msea.2007.10.051

[21] Y. Xu, H. Nagaumi, Y. Han, G. Zhang, T. Zhai: submitted to Journal of Alloys and Compounds (2016).

[22] G. Gottstein, Physical Foundations of Materials Science, Springer, Berlin (1996).