The Effects of Two-Stage Aging on the Microstructure and Mechanical Properties of the New Al-Si-Cu-Mg Alloy

Abstract:

Two-stage aging treatments were applied to Al-6Si-2Cu-0.5Mg casting alloy, and the influence of aging treatment parameters on the microstructure and mechanical properties was investigated. The experimental results indicated that the microstructure and mechanical properties of Al-6Si-2Cu-0.5Mg alloy were significantly influenced by the aging time and temperature, and the elongation remarkably increased with the aging time increasing before 7 h. In the case of the alloy aged at 200°Cfor 2h, higher hardness and tensile strength were obtained, which may be attributed to precipitation of a large amount of Cu-rich phases. However, the higher elongation was achieved in the alloy under 200°C aging treatment for 5h, while its hardness and tensile strength slightly decreased. It is mainly due to the amount of the Cu-rich phases decrease slightly, but the morphology of the phases evolved from plate-like to bulk-like structure.

• Periodical: Materials Science Forum (Volume 850)
• Pages: 581-586
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.850.581
• Online since: March 2016
• Authors: Yan Zheng, Cong Xu, Wen Long Xiao, Hiroshi Yamagata, Guo Fu Ji, Ming Juan Yang, Chao Li Ma
• Keywords: Cu-Rich Precipitates, Mechanical Properties, Microstructure, Two-Aging Treatment

References

[1] Liu Fang, Yu Fuxiao, Zhao Dazhi, Zuo Liang. Microstructure and mechanical properties of an Al–12. 7Si–0. 7Mg alloy processed by extrusion and heat treatment Mater Sci & Eng A 528 (2011) 3786-3790.

DOI: 10.1016/j.msea.2011.01.041

[2] I. Aguilera Luna, H. Manxha Molinar, M.J. Castro Román, J.C. Escobedo Bocardo, M. Herrera Trejo. Improvement of the tensile properties of an Al-Si-Cu-Mg aluminum industrial alloy by using multi stage solution heat treatments. Mater Sci & Eng A 561(2013).

DOI: 10.1016/j.msea.2012.10.064

[3] E. Sjölander, S. Seifeddine. The heat treatment of Al-Si-Cu-Mg casting alloys. J Mater Process Tech, 210 (2010) 1249-1259.

DOI: 10.1016/j.jmatprotec.2010.03.020

[4] E. Sjölander, S. Seifeddine. Artificial ageing of Al-Si-Cu-Mg casting alloys. Mater Sci & Eng A 528 (2011) 7402-7409.

DOI: 10.1016/j.msea.2011.06.036

[5] C. Cayron and P.A. Buffat. Transmission Electron Microscopy Study of the b' Phase (Al-Mg-Si Alloys) and QC Phase (Al-Cu-Mg-Si Alloys): Ordering Mechanism and Crystallographic Structure. Acta Materialia 48 (2000) 2639-2653.

DOI: 10.1016/s1359-6454(00)00057-4

[6] C. Wolverton. Crystal Structure and Stability of Complex Precipitate Phases in Al-Cu-Mg-(Si) and Al-Zn-Mg Alloys. Acta Materialia 49 (2001) 3129-3142.

DOI: 10.1016/s1359-6454(01)00229-4

[7] G. Wang, Q. Sun, L. Feng, L. Hui, C. Jing. Influence of Cu Content on Aging Behavior of AlSiMgCu Cast Alloys. Mater. Des. 28 (2007) 340-346.

DOI: 10.1016/j.matdes.2005.11.015

[8] G. Wang, X. Bian, X. Liu, J. Zhang. Effect of Mg on Age Hardening and Precipitation Behavior of an AlSiCuMg Cast Alloy. J. Mater. Sci. 39 (2004) 2535-2537.

DOI: 10.1023/b:jmsc.0000020022.19854.ac

[9] D. G. Eskin. Decomposition of Supersaturated Solid Solutions in Al-Cu-Mg-Si Alloys. J. Mater. Sci. 38 (2003) 279-290.

[10] X. Wang, S. Esmaeili, D. J. Lloyd. On the precipitation-hardening behavior of the Al-Mg-Si-Cu alloy AA6111. Metall. Mater. Trans. A 37 (2006) 2691-2699.

DOI: 10.1007/bf02586103

[11] X. Wang, W. J. Poole, S. Esmaeili, D. J. Lloyd, J. D. Embury. Precipitation strengthening of the aluminum alloy AA6111. Metall. Mater. Trans. A 34 (2003) 2913-2924.

DOI: 10.1007/s11661-003-0191-0

[12] D.J. Chakrabarti, D.E. Laughlin. Phase relations and precipitation in Al-Mg-Si alloys with Cu additions. Prog Mater Sci 49 (2004) 389-410.

DOI: 10.1016/s0079-6425(03)00031-8

[13] S.J. Andersen, H.W. Zandbergen, J. Jansen, H.W. Zandbergen, C.D. Marioara, S.J. Andersen. The crystal structure of the β' phase in Al–Mg–Si alloys. Acta Mater 55 (1998) 3815-3823.

DOI: 10.1016/j.actamat.2007.02.032

[14] Y. Zheng, W. Xiao, S. Ge, W. Zhao, S. Hanada, C. Ma. Effects of Cu content and Cu/Mg ratio on the microstructure and mechanical properties of AleSieCueMg alloys. J Alloys Compd 649 (2015) 291-296.

DOI: 10.1016/j.jallcom.2015.07.090

[15] M. Yıldırım, D. Özyürek. Heat treatment effect on thermo-mechanical fatigue and low cycle fatigue behaviors of A356. 0 aluminum alloy. Mater Design, 51 (2013) 767-774.

DOI: 10.1016/j.matdes.2012.08.066

[16] J.Y. Hwang, R. Banerjee, H.W. Doty, M.J. Kaufman. The effect of Mg on the structure and properties of Type 319 aluminum casting alloys. Acta Mater, 57 (2009) 1308-1317.

DOI: 10.1016/j.actamat.2008.11.021