Corrosion evaluation of Aluminum 6061-T6 exposed to sugarcane bioethanol-gasoline blends using the Stockwell transform

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2020-12, Vol.878, p.114667, Article 114667
• Main Authors: Rocabruno-Valdés, C.I., Escobar-Jiménez, R.F., Díaz-Blanco, Y., Gómez-Aguilar, J.F., Astorga-Zaragoza, C.M., Uruchurtu-Chavarín, J.
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Biofuels; Corrosion; Corrosion currents; Corrosion rate; Corrosion resistance; Corrosion tests; Electrochemical analysis; Electrochemical noise; Exposure; Fast Fourier transformations; Fourier transforms; Gasohol; Gasoline; Localized corrosion; Mixtures; Reaction kinetics; Signal processing; Stockwell transform; Sugarcane; Sugarcane bioethanol-gasoline blends
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2020.114667

This research presents the study of the corrosion type and the corrosion rate (CR) by signal processing of electrochemical noise (EN) of the Aluminum 6061-T6 (Al 6061-T6). This was exposed to bioethanol obtained from sugarcane (E100), regular gasoline (E0) and bioethanol - gasoline blends in following proportions; E5 (5% v/v bioethanol), E10 (10% v/v bioethanol), E20 or gasohol (20% v/v bioethanol) and E85 (85% v/v bioethanol). Three mathematical tools were used to perform the corrosion analysis: statistical method (SM), Fast Fourier transform (FFT), and Stockwell transform (ST) methods. The aim is to show the effectiveness of the ST method to define the corrosion type, resistance, as well as the CR. From the obtained results, the Al 6061-T6 in E100 and E85 blends showed greater susceptibility to the localized corrosion, and in E0, E5, E10, and E20 blends were susceptible to mixed corrosion . Similar values of resistance and CR were obtained by the analyzed methods. The Al 6061-T6 immersed in the bioethanol-gasoline blends achieved resistance values between 1×105 Ω cm2 and 1×1010 Ω cm2. The corrosion current density values (icorr) for all working electrodes were less than 2.1×10−4 mA/cm2, these values are considered low and insignificant. The ST is a powerful tool capable of analyzing the electrochemical behavior of aluminum alloy exposed to different solutions of bioethanol-gasoline blends. This mathematical model turned out to be efficient in determining the corrosion resistance, corrosion type, and kinetics of the process. Its application could be extended to the study of the corrosion of other metals in contact with other biofuels. •Corrosion analysis of the 6061-T6 aluminum alloy exposed to sugarcane bioethanol-gasoline blends.•Stockwell transform analysis for classifying the corrosion type.•Corrosion rate analysis by the statistical, FFT, and S-transform methods.•Comparison between the proposed method and the statistical and the FFT methods.