DEGRADATION ANALYSIS OF FIBER-METAL LAMINATES UNDER SERVICE CONDITIONS TO PREDICT THEIR DURABILITY

Abstract

A Fibre-Metal Laminate (FML) is an advanced material expected to possess higher mechanical properties than its sole constituents. Yet, only few studies focus on their durability. Thus, the aim of this study is to analyse the corrosion behaviour of FMLs based on carbon fibre composite (CFRP) and stainless steel in a sodium chloride solution. To fulfil this purpose, potentiodynamic polarisation and electrochemical impedance spectroscopy were utilized. It has been observed that, as an FML, the carbon composite and the stainless steel would effectively form an electrochemical cell, where the composite acts as a cathode and the stainless steel as an anode. Moreover, this galvanic corrosion is accompanied by pitting corrosion of the stainless steel electrode. Also the impedance data recorded has shown that EIS is the most suitable method for quantifying the polarisation resistance, whereas the polarisation technique is appropriate to measure both the mixed current density and the mixed potential of a CFRP/stainless-steel-hybrid laminate. Accordingly, carrying out potentiodynamic polarisation and EIS is a powerful approach to predict the galvanic corrosion behaviour of FMLs under service conditions.