Abstract
The influence of the ß-Mgi7Ali2 phase and, to a lesser degree, the solute content in the a-Mg matrix on the corrosion resistance of Mg alloys was investigated by cyclic potentiodynamic polarization and potentiostatic polarization tests using AZ31B, AM30 and AM60B in contact with a mildly aggressive near-neutral saline solution. Results showed that all three Mg alloys corrode in a partially protective state under open circuit conditions in the test solution. It was also determined that the surface film formed on each exhibits a similar apparent breakdown potential. This indicates that microstructure parameters such as the presence of the ß-phase and the solute content of the a-Mg matrix do not strongly influence the factors controlling the breakdown of the surface films formed. It was further determined that the moderately improved protectiveness of the surface film, rather than the distribution of the ß-MgnAli2 phase, is responsible for the improved (short-term) corrosion resistance exhibited by AM60B at potentials below the breakdown potential.
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References
G. Cole, “Summary of Magnesium Vision 2020: A North American Automotive Strategic Vision for Magnesium,” Magnesium Technology 2007, ed. R.S. Beals et al., (Warrendale, PA: TMS, 2007), 35–40.
E.A. Nyberget al., “Magnesium for Future Autos,” Adv. Mater. Processes, 166 (10) (2008), 35–37.
G.L Makar, J. Kruger, “Corrosion of Magnesium,” Int. Mater. Rev., 38 (1993), 138–153.
G. Song and A. Atrens, “Understanding Magnesium Corrosion: A Framework for Improved Alloy Performance,” Adv. Eng. Mater, 5 (2003), 837–858.
E. Ghali et al., “General and Localized Corrosion of Magnesium Alloys: A Critical Review,” J. Mater. Eng. Perform., 13 (2004), 7–23.
G. L. Song et al., “Corrosion Behaviour of AZ21, AZ501 and AZ91 in Sodium Chloride,” Corros. Sci, 40 (1998), 1769–1791.
M. Jonsson and D. Persson, “The Influence of Microstructure on the Atmospheric Corrosion Behaviour of Magnesium Alloys AZ91D and AM50,” Corros. Sci., 52 (2010), 1077–1085.
G. Ballerini et al., “About Some Corrosion Mechanisms of AZ91D Magnesium Alloy,” Corros. Sci., 47 (2005), 2173–2184.
A. Pardo et al., “Corrosion Behaviour of Magnesium/ Aluminum Alloys in 3.5 wt.% NaCl,” Corros. Sei., 50 (2008), 823–834.
O. Lunder et al., “The Role of Mgi7Ali2 Phase in the Corrosion of Mg Alloy AZ91,” Corrosion, 45 (1989), 741–748.
G. L. Song and A. Atrens, “Corrosion Mechanisms of Magnesium Alloys,” Adv. Eng. Mater, 1 (1999), 11–33.
G. L. Song, “Recent Progress in the Corrosion and Protection of Magnesium Alloys,” Adv. Eng. Mater., 7 (2005), 563–586.
O. Lunder et al., “Effect of Mn Additions on the Corrosion Behaviour of Mould-Cast Magnesium ASTM AZ91,” Corrosion, 43 (1987), 291–295.
M-C. Zhao et al., “An Exploratory Study of the Corrosion of Mg Alloys during Interrupted Salt Spray Testing,” Corros. Sci, 51 (2009), 1277–1292.
L. Wang et al., “Influence of Chloride, Sulfate and Bicarbonate Anions on the Corrosion Behavior of AZ31 Magnesium Alloy,” J. Alloy Compd, 496 (2010) 500–507.
L. Wang etal., “Corrosion Behavior of Mg, AZ31, and AZ91 Alloys in Dilute NaCl Solutions,” J. Solid State Electro-chem., 14 (2010), 1897–1907.
R. Tunold et al., “The Corrosion of Magnesium in Aqueous Solution Containing Chloride Ions,” Corros. Sci. 17 (1977), 353–365.
G. Williams and H.N. McMurray, “Localized Corrosion of Magnesium in Chloride-Containing Electrolyte Studied by a Scanning Vibrating Electrode Technique,” J. Electrochem. Soc., 155 (7) (2008), C340-C349.
G. Song et al., “The Electrochemical Corrosion of Pure Magnesium in 1 N NaCl,” Corros. Sci., 39 (1997), 855–875.
L. Wang et al., “XPS Study of the Surface Chemistry on AZ31 and AZ91 Magnesium Alloys in Dilute NaCl Solution,” Appl. Surf. Sci., 256 (2010) 5807–5812.
R.G. Kelly, “Electrochemical Thermodynamics and Kinetics of Relevance to Corrosion,” Electrochemical Techniques in Corrosion Science and Engineering, ed. R.G. Kelly et al., (New York, NY: Marcel Dekker, Inc. 2003), 45.
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Hu, Y., Kish, J.R., McDermid, J.R., Zheng, W. (2012). Effect of some Microstructural Parameters on the Corrosion Resistance of Magnesium Alloys. In: Mathaudhu, S.N., Sillekens, W.H., Neelameggham, N.R., Hort, N. (eds) Magnesium Technology 2012. Springer, Cham. https://doi.org/10.1007/978-3-319-48203-3_50
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DOI: https://doi.org/10.1007/978-3-319-48203-3_50
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