Corrosion Inhibition of Dicarboxylic Acids for Aluminium Alloy in Simulated Coolant Solution for Wind Turbine

The corrosion inhibition of three kinds of dicarboxylic acid inhibitors (succinic acid, adipic acid and sebacic acid) on A356 aluminum alloy in simulated coolant for wind turbine was investigated by electrochemical impedance spectroscopy (EIS) and polarization curves measurement. The molecular parameters of dicarboxylic acids were calculated by PM3 semi-empirical quantum chemistry method. The correlation between the molecular structure of dicarboxylic acids and their corrosion inhibition was discussed. Succinic acid, adipic acid and sebacic acid were all anodic corrosion inhibitors, which had obvious inhibition effect on the electrochemical anodic process of aluminum alloy corrosion, and there was an extreme effect on the corrosion inhibition of aluminum alloy. Adipic acid had the best corrosion inhibition, and its inhibition efficiency reached 93.5%. The dicarboxylic acids could form the inhibitive film on the aluminum alloy surface via the coordination between carboxylate group and aluminium ions.