Evaluation of Susceptibility to Exfoliation Corrosion of Al - Li 2060 Aluminum Lithium Alloy Using Electrochemical Techniques in EXCO Solution

摘要

Aluminum Alloys are widely used for aircraft application in both commercial and military fields. The increasing development in performance and efficiency has led to Al-Cu-Li Alloys, as these are capable of being lighter while achieving similar or superior levels of mechanical properties of their commonly used counterparts. The need to evaluate new alloys such as Al 2060 to their susceptibility to corrosion, especially Exfoliation Corrosion (EFC), becomes evident as this corrosion mechanism is known to be one of the main reasons of failure of aluminum alloys. The aim of this paper is to use electrochemical and surface analysis techniques to evaluate the susceptibility to EFC in Al 2060 in the Exfoliation Corrosion (EXCO) solution proposed in ASTM G34, propose a mechanism and describe the different stages of the damage evolution of the material. Electrochemical techniques include Open Circuit Potential (OCP), Cyclic Potentiodynamic Polarization (CPP), Galvanostatic Polarization (GS), Electrochemical Impedance Spectroscopy (EIS) and Electrochemical Noise (EN).