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Anodization: Recent Advancements on Corrosion Protection of Brake Calipers
Technical Paper
2020-01-1626
ISSN: 2641-9637, e-ISSN: 2641-9645
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English
Abstract
Brake calipers for high-end cars are typically realized using Aluminum alloys, with Silicon as the most common alloying element. Despite the excellent castability and machinability of Aluminum-Silicon alloys (AlSix), anodization is often required in order to increase its corrosion resistance. This is particularly true in Chlorides-rich environments where Aluminum can easily corrode. Even if anodization process is known for almost 100 years, anodization of AlSix -based materials is particularly challenging due to the presence of eutectic Silicon precipitates. These show a poor electric conductivity and a slow oxidation kinetics, leading to inhomogeneous anodic layers. Continuous research and process optimization are required in order to develop anodic layers with enhanced morphological and electrochemical properties, targeting a prolonged resistance of brake calipers under endurance corrosive tests (e.g. >1000 hours Neutral Salt Spray (NSS) tests). In this manuscript a lab-scale anodization setup is used to investigate the interplay between process parameters, oxide layer morphology and corrosion protection capability. The influence of high anodization steps (AS) and low rest steps (RS) in pulsed anodization waveforms is investigated with respect to the homogeneity and compactness of the obtained oxide layers. In comparison with a conventional set of anodization parameters, which is taken as a standard, the following level of performance are achieved: 1) increase of the corrosion potential (Ecorr) of +98mV; 2) increase of the anodic breakdown potential (Ebp) of +362mV; 3) reduction of the corrosion rate of a factor six; and 4) a polarization resistance 1.5 times higher. This work identifies key parameters in the anodization of Aluminum-Silicon alloys and propose new electrochemical figures of merit in order to: a) extend the corrosion resistance of future braking systems; and b) evaluate ex-situ the anodic layer electrochemical performance.
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Bandiera, M., Bonfanti, A., Bestetti, M., and Bertasi, F., "Anodization: Recent Advancements on Corrosion Protection of Brake Calipers," SAE Int. J. Adv. & Curr. Prac. in Mobility 3(2):973-979, 2021, https://doi.org/10.4271/2020-01-1626.Data Sets - Support Documents
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Also In
SAE International Journal of Advances and Current Practices in Mobility
Number: V130-99EJ; Published: 2021-04-16
Number: V130-99EJ; Published: 2021-04-16
References
- Basavakumar , K.G. , Mukunda , P.G. , and Chakraborty , M. Influence of Grain Refinement and Modification on Microstructure and Mechanical Properties of Al-7Si and Al-7Si-2.5 Cu Cast Alloys Materials Characterization 59 3 283 289 2003 https://doi.org/10.1016/j.matchar.2007.01.011
- Bandiera , M. , Pin , S. , Bonfanti , A. , and Bertasi , F. 2020
- Bandiera , M. , Bonfanti , A. , Mauri , A. , Mancini , A. et al. 2020
- Fratila-Apachitei , L.E. , Tichelaar , F.D. , Thompson , G.E. , Terryn , H. et al. A Transmission Electron Microscopy Study of Hard Anodic Oxide Layers on AlSi (Cu) Alloys Electrochimica Acta 49 19 3169 3177 2004 https://doi.org/10.1016/j.electacta.2004.02.030
- Gulec , A.E. , Gencer , Y. , and Tarakci , M. The Characterization of Oxide Based Ceramic Coating Synthesized on Al-Si Binary Alloys by Microarc Oxidation Surface and Coatings Technology 269 100 107 2015 https://doi.org/10.1016/j.surfcoat.2014.12.031
- Bozza , A. , Giovanardi , R. , Manfredini , T. , and Mattioli , P. Pulsed Current Effect on Hard Anodizing Process of 7075-T6 Aluminium Alloy Surface and Coatings Technology 270 139 144 2015 https://doi.org/10.1016/j.surfcoat.2015.03.010
- Mohammadi , I. , and Abdollah , A. Modification of Nanostructured Anodized Aluminum Coatings by Pulse Current Mode Surface and Coatings Technology 278 48 55 2015 https://doi.org/10.1016/j.surfcoat.2015.08.004
- Bertasi , F. Mancini , A. , Bandiera , M. , Pin , S. et al. Interplay between Composition and Electrochemical Performance at the Pad-disc Interface Proceedings of EUROBRAKE 2019
- Zoski , C.G. Handbook of Electrochemistry Elsevier 2006 978-0-444-51958-0
- Yokoyama , K. , Konno , H. , Takahashi , H. , and Nagayama , M. Advantages of Pulse Anodizing Plat. Surf. Finish. 69 62 65 1982
- Bononi , M. , Giovanardi , R. , Bozza , A. , and Mattioli , P. Pulsed Current Effect on Hard Anodizing Process of 2024-T3 Aluminium Alloy Surface and Coatings Technology 289 110 117 2016 https://doi.org/10.1016/j.surfcoat.2016.01.056
- Mohedano , M. , Matykina , E. , Arrabal , R. , Mingo , B. et al. PEO of Pre-anodized Al-Si Alloys: Corrosion Properties and Influence of Sealings Applied Surface Science 346 57 67 2015 https://doi.org/10.1016/j.apsusc.2015.03.206
- Zhu , B. , Seifeddine , S. , Persson , P.O. , Jarfors , A.E. et al. A Study of Formation and Growth of the Anodized Surface Layer on Cast Al-Si Alloys Based on Different Analytical Techniques Materials & design 101 254 262 2016 https://doi.org/10.1016/j.matdes.2016.04.013
- Mehdizade , M. , Soltanieh , M. , and Eivani , A.R. Investigation of Anodizing Time and Pulse Voltage Modes on the Corrosion Behavior of Nanostructured Anodic Layer in Commercial Pure Aluminum Surface and Coatings Technology 358 741 752 2019 https://doi.org/10.1016/j.surfcoat.2018.08.046
- Kwolek , P. , Drapała , D. , Krupa , K. , Obłój , A. et al. Mechanical Properties of a Pulsed Anodised 5005 Aluminium Alloy Surface and Coatings Technology 383 125233 2020 https://doi.org/10.1016/j.surfcoat.2019.125233