Modeling and Analysis of Corrosion of Aluminium Alloy 6060 Using Electrochemical Impedance Spectroscopy (EIS)
Abstract
1. Introduction
2. Materials and Methods
2.1. Materials and Coating Production
2.2. Experimental Procedure
3. Results and Discussion
3.1. Surface Morphology
3.2. Electrochemical Characterization
3.3. Proposed Equivalent Electrical Circuit Models
Al Samples | Rs (Ω) | CPE1 (S × sa) | α1 | CPE2 (S × sa) | α2 | CPE3 (S × sa) | α3 | R1 (MΩ) | R2 | Rct | W (S × s1/2) |
---|---|---|---|---|---|---|---|---|---|---|---|
Initial | 6.63 | 9.95 × 10−6 | 0.87 | - | - | - | - | - | - | 13 kΩ | - |
Clear anodized | 26.3 | 6 × 10−10 | 1 | 2 × 10−9 | 0.95 | - | - | - | 0.7 ΜΩ | 1.48 ΜΩ | 1.2 × 10−6 |
Black Anodized | 1 | 4 × 10−10 | 0.92 | 2.9 × 10−9 | 0.9 | - | - | - | 4.21 MΩ | 0.74 ΜΩ | 68 × 10−5 |
Pre-anodized and painted | 0.1 | 1.74 × 10−9 | 0.95 | 1.8 × 10−9 | 0.93 | 1.4 × 10−9 | 0.9 | 7.5 | 2 kΩ | 0.47 MΩ | 1.3 × 10−5 |
4. Conclusions
- Surface treatments significantly improve corrosion resistance. Anodized samples demonstrate an approximately 30 times lower corrosion rate, while the pre-anodized and painted samples offer the highest protection, with a corrosion rate nearly 1000 times lower than that of the untreated aluminum.
- The clear anodized sample showed an almost ideal dielectric behavior (α~1) and a charge transfer resistance of 1.48 MΩ, indicating a uniform oxide. The clear anodized sample had higher anodic resistance but lower Rct (0.74 MΩ), suggesting reduced oxide quality, likely due to porosity or dye effects.
- The pre-anodized and painted samples demonstrate a complex multilayer electrochemical behavior that explains its superior protective performance. The outer layer exhibits very high resistance (7.5 MΩ) and excellent dielectric properties (α = 0.95), indicating an effective barrier against corrosion.
- The high values of resistance for the anodized samples indicate that the sealing process was highly effective.
- The thickness of the anodized layers correlates well with the SEM results.
Author Contributions
Funding
Conflicts of Interest
References
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Sample | Ecorr [mV] | Icorr [A/cm2] | βa | βc | Corrosion Rate [mmpy] |
---|---|---|---|---|---|
Initial | −0.756 | 9 × 10−7 | 0.022 | −0.52 | 0.03 |
Clear anodized | −0.702 | 2.72 × 10−8 | 0.78 | −0.52 | 0.0009 |
Black anodized | −0.722 | 4 × 10−8 | 1.19 | −0.86 | 0.0014 |
Pre-anodized and painted | −0.729 | 9.72 × 10−10 | 0.91 | −0.46 | 0.00003 |
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Baxevani, A.; Lamprou, E.; Mavropoulos, A.; Stergioudi, F.; Michailidis, N.; Tsoulfaidis, I. Modeling and Analysis of Corrosion of Aluminium Alloy 6060 Using Electrochemical Impedance Spectroscopy (EIS). Alloys 2025, 4, 17. https://doi.org/10.3390/alloys4030017
Baxevani A, Lamprou E, Mavropoulos A, Stergioudi F, Michailidis N, Tsoulfaidis I. Modeling and Analysis of Corrosion of Aluminium Alloy 6060 Using Electrochemical Impedance Spectroscopy (EIS). Alloys. 2025; 4(3):17. https://doi.org/10.3390/alloys4030017
Chicago/Turabian StyleBaxevani, Aikaterini, Eleni Lamprou, Azarias Mavropoulos, Fani Stergioudi, Nikolaos Michailidis, and Ioannis Tsoulfaidis. 2025. "Modeling and Analysis of Corrosion of Aluminium Alloy 6060 Using Electrochemical Impedance Spectroscopy (EIS)" Alloys 4, no. 3: 17. https://doi.org/10.3390/alloys4030017
APA StyleBaxevani, A., Lamprou, E., Mavropoulos, A., Stergioudi, F., Michailidis, N., & Tsoulfaidis, I. (2025). Modeling and Analysis of Corrosion of Aluminium Alloy 6060 Using Electrochemical Impedance Spectroscopy (EIS). Alloys, 4(3), 17. https://doi.org/10.3390/alloys4030017