Electrochemical characterization of alloy segregation in the near-surface deformed layer of welded zones of an Al-Cu-Li alloy using scanning electrochemical microscopy

Author(s)

da Silva, Rejane Maria P. ; Izquierdo, Javier ; Milagre, Mariana X. ; Araujo, Joao Victor de S. ; Antunes, Renato A. ; Souto, Ricardo M. ; Costa, Isolda

• Document type: Journal article
• Source: Electrochimica Acta; v. 427, p. 7-pg., 2022-07-20.

Abstract

The development of heterogeneous electrochemical activity in the welded zones of aluminum alloy 2098-T351 by friction stir welding (FSW) associated with the formation of a near-surface deformed layer (NSDL) upon exposure to an aqueous chloride-containing solution was characterized using scanning electrochemical microscopy (SECM) in potentiometric operation. A solid-contact Mg2+ ion-selective microelectrode allowed in situ monitoring of the corrosion reactions sites for magnesium dissolution from different zones of the FSW weld upon exposure to a chloride-containing aqueous environment. In this way, localized corrosion reactions developing in the galvanically coupled joint/heat affected zones (WJ/HAZ) of the weld were detected and imaged with spatial resolution. The most active domains for local Mg2+ concentrations were associated with the HAZ of the retreating side (RS), and these corresponded to Mg oxidation from the Mg-enriched oxide bands in NSDL. (AU)

• FAPESP's process: 13/13235-6 - Investigation on the localized corrosion and the fatigue corrosion resistance of high strength aluminum alloys joined by friction stir welding (FSW)
• Grantee: Isolda Costa
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/06880-6 - Use of Localized Electrochemical Techniques for the Study of Corrosion of of High Strength Aluminum Alloys Joined by Friction (FSW).
• Grantee: Rejane Maria Pereira da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/11427-1 - Micro-electrochemical techniques to study the localized corrosion in Al-Cu-Li alloys joined by friction stir welding (FSW)
• Grantee: Rejane Maria Pereira da Silva
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor