The corrosion inhibition mechanisms of Ce(Ⅲ) ions and triethanolamine on graphite-AA2024-T3 galvanic couples revealed by localised electrochemical techniques

摘要

The inhibition mechanism of cerium chloride and triethanolamine on the galvanic corrosion of AA2024-T3/graphite in NaCl electrolyte was investigated by localised electrochemical techniques. Quasi-simultaneous measurements of ionic current densities and pH were performed by the Scanning Vibrating Electrode Technique (SVET) and Scanning Ion-Selective Electrode Technique (SIET). Surfaces were analysed by Scanning Electron Microscopy coupled with Energy Dispersive X-ray (SEM-EDX) and X-Ray Photoelectron Spectroscopy (XPS). This work follows a recent publication (Coelho et al. 2018) and discusses the effect of inhibitors on two AA2024-T3/graphite galvanic couples, constructed with two different areas ratio, evidencing that this parameter significantly influences the corrosion and corrosion inhibition process.