R. Ambat et Es. Dwarakadasa, STUDIES ON THE INFLUENCE OF CHLORIDE-ION AND PH ON THE ELECTROCHEMICAL-BEHAVIOR OF ALUMINUM ALLOY-8090 AND ALLOY-2014, Journal of Applied Electrochemistry, 24(9), 1994, pp. 911-916
The influence of chloride ion concentration and pH (2.0, 6.0 and 11.0)
on the corrosion behaviour of 8090 (Al-Li-Cu-Mg-Zr) and 2014 (Al-4.4%
Cu) alloys has been studied in NaCl solution using a potentiodynamic p
olarization technique. The corrosion rate for both the alloys was high
at pH values of 2.0 and 11.0 as compared to that at pH 6.0, and the r
ate increased in chloride ion concentration at all pH levels. A simila
r result was found for the passive current density. Increase in pH cha
nged the slope of the cathodic polarization curve by changing the cath
odic reaction. Increasing the chloride ion concentration decreased the
cathodic reaction rate. On the other hand, the anodic reaction rate i
ncreased with increase in chloride ion concentration. The open circuit
corrosion potential and the pitting potential shifted in the active (
negative) direction with increasing pH and chloride ion concentration.
The i(p) values for 8090-T851 were slightly lower than those for 2014
-T6.