Corrosion Resistance of Alloy 2024 Anodized on Sulfuric-Citric Acid

Aluminium alloys are used on aerospace and automotive industry due to excellences mechanical properties. Unfortunately, aluminium alloys are susceptible to corrosion and that limit them in some corrosive environments. The aim of this work is researching the characteristics of anodized film generated with sulfuric-citric acid through to electrochemical techniques. For matrix material, an Aluminium (Al) 2024 alloy was used applying a mixt of sulfuric and citric acid with a current of 0.01 and 1 A at 25°C each one while 30 minutes. Electrochemical evaluation used was cyclic potentiodynamic polarization curves (CPPC) and Electrochemical Impedance Spectroscopy (EIS) in NaCl at 3.5% wt. Scanning Electron Microscopy (SEM) was used to determinate morphology and thickness of coating. Results shows that aluminium anodized with mixt of sulfuric-citric acid presented less pitting corrosion resistance with out present a significative difference in surface morphology.