Corrosion mitigation of AA6082, Copper-ETP, and their galvanic couple using ▫$Ce(OAc)_{3}$▫, ▫$Na_{2}SO_{4}$▫, and 1H-BTA in chloride solution

Trdan, Uroš (author), Logar, Andraž (author), Klobčar, Damjan (author), Milošev, Ingrid (author), Kapun, Barbara (author), Rodič, Peter (author)

Galvanic coupling between aluminium alloy 6082 and copper (Cu-ETP) accelerates corrosion through anodic dissolution of aluminium, posing serious durability challenges for mixed-metal structures. This study investigates the inhibition mechanisms of cerium acetate (▫$Ce(OAc)_{3}$▫), sodium sulphate (▫$Na_{2}SO_{4}$▫), and 1H-benzotriazole (1H-BTA), individually and in combination, on AA6082, Cu-ETP, and their galvanic couple in 0.1 M NaCl solution. The inhibitors’ performance was evaluated using potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and salt spray testing. ▫$Ce(OAc)_{3}$▫ and ▫$Na_{2}SO_{4}$▫ promoted the formation of cerium oxide films on AA6082, while 1H-BTA adsorbed on Cu-ETP, forming a compact film that suppressed anodic dissolution and cathodic oxygen reduction. The combined inhibitor system, compared to the uninhibited system, significantly reduced galvanic corrosion current by a factor ∼4.5 (▫$2.6μA/cm^{2}$▫ vs. ▫$11.8μA/cm^{2}$▫) and enhanced pitting resistance by shifting the pitting potential of AA6082 to more noble values. Furthermore, EIS results confirmed the improved stability of the passive films on Cu-ETP after 72 h of immersion in inhibitor mixture (▫$∣Z_{0.01 Hz}$▫∣ = 4.4 ▫$MΩcm^{2}$▫). SEM and salt spray results showed reduced corrosion and uniform protective deposits, with treated AA6082 retaining over 92% of its original volume after 42 days of exposure. This work demonstrates a synergistic inhibition strategy combining cerium salts and organic molecules to protect aluminium–copper assemblies in aggressive environments.

• Language: English
• Keywords: AA6082, Cu-ETP, corrosion inhibition, cerium acetate, benzotriazole, galvanic coupling
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: Str. 2422-2436
• Numbering: Vol. 40
• PID: 20.500.12556/RUL-177782
• UDC: 620.193:621.357
• ISSN on article: 2238-7854
• DOI: 10.1016/j.jmrt.2025.12.290
• COBISS.SI-ID: 263725571
• Publication date in RUL: 07.01.2026

Record is a part of a journal

• Title: Journal of Materials Research and Technology
• Shortened title: J. Mater. Res. Technol.
• Publisher: Elsevier
• ISSN: 2238-7854
• COBISS.SI-ID: 519699737

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: zaviranje korozije, cerijev acetat, benzotriazol, galvansko povezovanje