Effect of the cooling rate on the electrochemical behaviour of 2017 aluminium alloy

Effect of the cooling rate on the electrochemical behaviour of 2017 aluminium alloy

Szklarz, Z. Krawiec, H. Rogal, Ł. 

AGH University of Science and Technology, Faculty of Foundry Engineering, 23 Reymonta St., Krakow, 30-059, Poland

Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., Krakow, 30-059, Poland

Page: 
25-32
|
DOI: 
https://doi.org/10.3166/acsm.40.25-32
Received: 
1 October 2015
|
Accepted: 
7 January 2016
|
Published: 
11 May 2016
| Citation

OPEN ACCESS

Abstract: 

The influence of cooling rate on the microstructure and on the electrochemical behaviour of 2017 aluminium alloy is studied in this work. The electrochemical measurements were conducted at the mesoscale by using Electrochemical Microcell Technique (EMT) with 300 μm capillary in 0.1 M NaCl aqueous solution. The microstructure of specimens from the internal part of ingot and quick cooled sample were determined by optical microscope and SEM/EDX analysis. The corrosion behavior and the passive properties were studied by means of Open Circuit Potential (OCP) and Electrochemical Impedance Spectroscopy (EIS). It is observed that slow solidification causes irregular grain growth with very large and very small grains. Moreover heterogeneities in the matrix were observed in the form of needle shaped particles. High rate of cooling causes the presence of quite small regular grains and homogenous matrix. The specimens of quick cooled 2017 alloy exhibit higher corrosion potential and the dissolution of metal starts at higher anodic potential compared to the non-treated specimens.

1. Introduction
2. Experimental Procedure
3. Results and Discussion
4. Conclusions
  References

[1] Kaufman, J.G., Rooy, E.L.(2004). Aluminium Alloy Castings. Properties Processes and Applications. 

[2] Brown, J.R. (1999). Foseco Non-Ferrous Foundryman's Handbook. 

[3] Polmear, I.J. (2006). Light Alloys - From Traditional Alloys to Nanocrystals. 

[4] Zolotorevsky, V.S., Belov, N.A., Glazoff, M.V. (2007). Casting Aluminum Alloys. Casting Aluminum Alloys. http://www.sciencedirect.com/science/book/9780080453705. ISBN: 978-008045370-5. https://doi.org/10.1016/B978-0-08-045370-5.X5001-9

[5] Katgerman, L., Eskin, D. (2003). Hardening Annealing and Aging, Handbook of Aluminium, 1. Physical Metallurgy and Processes

[6] Birbilis, N., Buchheit, R.G. (2005). Electrochemical characteristics of intermetallic phases in aluminum alloys: An experimental survey and discussion. Journal of the Electrochemical Society, 152 (4): B140-B151. https://doi.org/10.1149/1.1869984

[7] Niԟancioğlu, K. (1990). Electrochemical behavior of aluminum-base intermetallics containing iron. Journal of the Electrochemical Society, 137 (1): 69-77. https://doi.org/10.1149/1.2086441

[8] Guillaumin, V., Mankowski, G. (1998). Localized corrosion of 2024 T351 aluminium alloy in chloride media. Corrosion Science, 41(3): 421-438. https://www.journals.elsevier.com/corrosion-science. https://doi.org/10.1016/S0010-938X(98)00116-4

[9] Campestrini, P., Van Westing, E.P.M., Van Rooijen, H.W., De Wit, J.H.W. (2000). Relation between microstructural aspects of AA2024 and its corrosion behaviour investigated using AFM scanning potential technique. Corrosion Science, 42 (11): 1853-1861. https://doi.org/10.1016/S0010-938X(00)00002-0

[10] Little, D.A., Connolly, B.J., Scully, J.R. (2007). An electrochemical framework to explain the intergranular stress corrosion behavior in two Al-Cu-Mg-Ag alloys as a function of aging. Corrosion Science, 49(2): 347-372. https://doi.org/10.1016/j.corsci.2006.04.024

[11] Ambat, R., Davenport, A.J., Scamans, G.M., Afseth, A. (2006). Effect of iron-containing intermetallic particles on the corrosion behaviour of aluminium. Corrosion Science, 48 (11): 3455-3471. https://doi.org/10.1016/j.corsci.2006.01.005

[12] Krawiec, H., Vignal, V., Szklarz, Z. (2009). Local electrochemical studies of the microstructural corrosion of AlCu4Mg1 as-cast aluminium alloy and influence of applied strain. Journal of Solid State Electrochemistry, 13(8): 1181-1191. https://doi.org/10.1007/s10008-008-0638-8

[13] Krawiec, H., Szklarz, Z., Vignal, V. (2012). Influence of applied strain on the microstructural corrosion of AlMg2 as-cast aluminium alloy in sodium chloride solution. Corrosion Science, 65: 387-396.  https://doi.org/10.1016/j.corsci.2012.08.047

[14] Muller, I.L., Galvele, J.R. (1977). Pitting potential of high purity binary aluminium alloys-I. AlCu alloys. Pitting and intergranular corrosion. Corrosion Science, 17(3): 179-189,191-193. https://doi.org/10.1016/0010-938X(77)90044-0

[15] Muller, I.L., Galvele, J.R. (1977). Pitting potential of high purity binary aluminium alloys-II. Al‒Mg and Al‒Zn alloys. Corrosion Science, 17 (12): 995-1007. https://doi.org/10.1016/S0010-938X(77)80014-0

[16] Vignal, V., Krawiec, H., Heintz, O., Mainy, D. (2013). Passive properties of lean duplex stainless steels after long-term ageing in air studied using EBSD, AES, XPS and local electrochemical impedance spectroscopy. Corrosion Science, 67: 109-117. https://doi.org/10.1016/j.corsci.2012.10.009