Effects of RE Micro-Alloying Additions on the Corrosion Behavior of an Al-Mg-Si Alloy

Abstract:

AlMg5Si1-xRE (x=0%, 0.9%) alloys were prepared by resistance melting method, and the phases of alloy were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of RE (rare earth) on the corrosion resistance of AlMg5Si1 alloy immersed in seawater in different time were investigated by potential measurements and electrochemical impedance spectroscopy. The results showed that the strengthening phase β (Mg2Si) was short rod like and dispersing distributed in α (Al) in the AlMg5Si1 alloy after adding 0.9% RE. Under the conditions of seawater immersion, the corrosion rate of the AlMg5Si1RE0.9 alloy was less than that of AlMg5Si1 alloy, and the corrosion rate of AlMg5Si1RE0.9 immersed 12h in seawater was the slowest, 5.7 uA·cm^-2. The improved corrosion resistance is due to the changes in microstructure and corrosion products.

• Periodical: Key Engineering Materials (Volume 729)
• Pages: 40-45
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.729.40
• Online since: February 2017
• Authors: Wei Bing Kong, Xin Xin Li, Xin Ping Hu*
• Keywords: AlMg5Si1, Corrosion, Electrochemical Impedance Spectroscopy, Potential Curve

References

[1] S. Nayak, N. B. Dahotre. Surface engineering of aluminum alloys for automotive engine applications. The Journal of the Minerals, Metals & Materials Society, 2004, 56(1): 46-48.

DOI: 10.1007/s11837-004-0272-6

[2] K. Weibing, W, Zhi, G. Changsheng, H. Xinping and H. Hu. Process optimization for high pressure die casting of marine propeller with a hypoeutectic Al-Si-Mg Alloy. Metallurgical Research & Technology, 2016, 113(4): 402-410.

DOI: 10.1051/metal/2016020

[3] R. S. Yassar, D. P. Field, H. Weiland. The effect of cold deformation on the kinetics of the β" precipitates in an Al-Mg-Si alloy. Metallurgical and Materials Transactions A. 2005, 36(8): 2059–(2065).

DOI: 10.1007/s11661-005-0326-6

[4] W. Hongfei, K. Weibing, H. Xinping. Designing of permanent die`s tensile specimen and the specimen`s tensile test. MATEC Web of Conferences, 2016, 67: 3009-3014.

[5] X. Ding, H. Cui, J. Zhang, H. Li, M. Guo. The effect of Zn on the age hardening response in an Al-Mg-Si alloy. Materials and Design. 2015, 65: 1229-1235.

DOI: 10.1016/j.matdes.2014.09.086

[6] M. Hosseinifar, D. V. Malakhov. Effect of Ce and La on microstructure and properties of a 6xxx series type aluminum alloy. Journal of Materials Science, 2008, 43(22): 7157–7164.

DOI: 10.1007/s10853-008-3022-2

[7] Y. Tsai, C. Chou, S. Lee, et al. Effect of trace La addition on the microstructures and mechanical properties of A356 (Al-7Si-0. 35Mg) aluminum alloys. Journal of Alloys and Compounds, 2009, 487(1-2): 157-162.

DOI: 10.1016/j.jallcom.2009.07.183

[8] S. Yingying, S. Min, H. Yuehui. Effects of Sc content on the mechanical properties of Al-Sc alloys. Rare Metals. 2010, 25(9): 451-455.

DOI: 10.1007/s12598-010-0148-6

[9] M. Stern, A.L. Geary. Electrochemical Polarization I . A theoretical analysis of the shape of polarization curves. J. Electrochem. Soc. 1957, 104(1): 56- 63.

DOI: 10.1149/1.2428473

[10] F. Lei, P. Qinglin, W. Lili, et al. Through-thickness inhomogeneity of localized corrosion in 7050-T7451 Al alloy thick plate. Journal of Central South University. 2015, 22(7): 2423-2434.

DOI: 10.1007/s11771-015-2769-2

[11] Y. Shi, Q. Pan, M. Li, et al. Effect of Sc and Zr additions on corrosion behavior of Al–Zn–Mg–Cu alloys. Journal of Alloys and Compounds. 2014 (612): 42-50.

DOI: 10.1016/j.jallcom.2014.05.128

[12] Z. Jinghuai, L. Zhe, Z. Milin, et al. Effect of Ce on microstructure, mechanical properties and corrosion behavior of high-pressure die-cast Mg-4Al-based alloy. Journal of Alloys and Compounds. 2011, 509(3): 1069-1078.

DOI: 10.1016/j.jallcom.2010.09.185