Potentiodynamic Tests of Magnesium Alloy AZ31 with Lithium Additive

Abstract:

The purpose of the study is to assess electrochemical corrosion resistance of magnesium alloy AZ31 with additives of 4.5, 7.5 and 15 % lithium in NaCl solutions. Corrosion tests were performed in solutions with concentration 0.01 2 M NaCl with application of electrochemical testing system VoltaLab®PGP201. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves by means of potentiodynamic method. Results of performed tests show unequivocally deterioration of corrosion characteristics of the alloy together with increase of molar concentration of NaCl solution. As chloride ions concentration increases, decrease of corrosion potential and polarisation resistance, as well as increase of corrosion current density are observed. Deterioration of corrosion characteristics of AZ31 alloy was shown with the increase of lithium content. It must be highlighted that irrespective of molar concentration of NaCl solution, there is also presence of pitting corrosion in the tested alloy. It proves that magnesium alloy AZ31-Li is not resistant to that type of corrosion. Test results prove that it is necessary to apply protective films on elements made of magnesium alloy with lithium additive.

• Periodical: Solid State Phenomena (Volume 211)
• Pages: 93-100
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.211.93
• Online since: November 2013
• Authors: Joanna Przondziono*, Witold Walke, Eugeniusz Hadasik, Stanisław Lalik
• Keywords: Anodic Polarisation Curves, Electrochemical Corrosion, Magnesium Alloy AZ31 with Lithium, Potentiodynamic Tests

References

[1] K.E. Oczoś, A. Kawalec, Light metals forming, Wydawnictwo Naukowe PWN, Warszawa, 2012 (in Polish).

[2] A. Kiełbus, D. Kuc, T. Rzychoń, Magnesium alloys – microstructure, properties and application. Monograph. Modern metallic materials - presence and future. Department of Materials Engineering and Metallurgy, Katowice, 2009 (in Polish).

[3] S. Rusz, L. Čížek, L.A. Dobrzański, S. Tylšar, J. Kedroň, ECAP methods application on selected non-ferrous metals and alloys, Archives of Materials Science and Engineering 43 (2010) 69-76.

DOI: 10.4028/www.scientific.net/msf.782.404

[4] M. Ullmann, H. Saleh, M. Schmitdchen, R. Kawalla, H.P. Vogt, Improvement of ductility for Twin Roll Cast and rolled AZ31 strips by use of Taguchi method, Archives of Civil and Mechanical Engineering 13 (2013) 1-6.

DOI: 10.1016/j.acme.2012.09.001

[5] A. Gontarz, Z. Pater, K. Drozdowski, Hammer forging process of lever drop forging from AZ31 magnesium alloy, Metalurgija 52 (2013) 359-362.

[6] W. Walke, E. Hadasik, J. Przondziono, D. Kuc, I. Bednarczyk, G. Niewielski, Plasticity and corrosion resistance of magnesium alloy WE43, Archives of Materials Science and Engineering 51 (2011) 16-24.

[7] Z. Cyganek, M. Tkocz, The effect of AZ31 alloy flow stress description on the accuracy of forward extrusion FE simulation results, Archives of Metallurgy and Materials 57 (2012) 199-204.

DOI: 10.2478/v10172-012-0010-y

[8] J. Tomczak, Z. Pater, T. Bulzak, Thermo-mechanical analysis of a lever preform forming from magnesium alloy AZ31, Archives of Metallurgy and Materials 57 (4) (2012) 1211-1218.

DOI: 10.2478/v10172-012-0135-z

[9] E. Hadasik, D. Kuc, T. Mikuszewski, Plasticity and microstructure of Mg-Li alloys, Hutnik. Wiadomości Hutnicze 78 (2011) 617-621 (in Polish).

[10] W. Walke, J. Przondziono, E. Hadasik, J. Szala, D. Kuc, Corrosion resistance of AZ31 alloy after plastic working in NaCl solutions. Journal of Achievements in Materials and Manufacturing Engineering 45 (2011) 132-140.

DOI: 10.1088/1757-899x/22/1/012017

[11] G. Song, A. Atrens, X. Wu, B. Zhang, Corrosion behaviour of AZ21, AZ501 and AZ91 in sodium chloride, Corrosion Science 40 (1998) 1769-1791.

DOI: 10.1016/s0010-938x(98)00078-x

[12] G. Song, A. Atrens, Corrosion mechanisms of magnesium alloys, Advanced Engineering Materials 1 (1999) 11-33.

[13] J. Przondziono, W. Walke, E. Hadasik, B. Jasiński, Electrochemical corrosion of magnesium alloy AZ31 in NaCl solutions, Acta Metallurgica Slovaca 16 (2010) 254-260.

DOI: 10.1007/978-3-030-15472-1_30

[14] J. Przondziono, W. Walke, E. Hadasik, J. Szala, J. Wieczorek, Corrosion resistance tests of magnesium alloy WE43 after extrusion, Metalurgija 52 (2) (2013) 242-246.

DOI: 10.4028/www.scientific.net/kem.607.31

[15] G. Song, A. Atrens, Understanding Magnesium Corrosion - A Framework for Improved Alloy Performance, Advanced Engineering Materials 5 (2003) 837-858.

DOI: 10.1002/adem.200310405

[16] J. Przondziono, W. Walke, A. Szuła, E. Hadasik, J. Szala, J. Wieczorek, Resistance to corrosion of magnesium alloy AZ31 after plastic working, Metalurgija 50 (2011) 239-243.

DOI: 10.4028/www.scientific.net/ssp.227.35

[17] A.J. Dolata, M. Dyzia, W. Walke, Influence of particles type and shape on the corrosion resistance of aluminium hybrid composites, Solid State Phenomena 191 (2012) 81-87.

DOI: 10.4028/www.scientific.net/ssp.191.81