采用电化学阻抗谱和极化曲线考察了3种二羧酸缓蚀剂(丁二酸、己二酸、癸二酸)在风电机模拟冷却液中对A356铝合金的缓蚀作用。采用PM3半经验量子化学计算方法,研究了二羧酸分子结构参数,讨论了二羧酸分子结构和缓蚀性能的相关性。结果表明:丁二酸、己二酸和癸二酸为阳极型缓蚀剂,对铝合金的腐蚀电化学阳极过程产生明显的抑制作用,且对铝合金的缓蚀存在极值效应;其中,己二酸的缓蚀效果最好,其缓蚀率达93.5%;二羧酸能通过羧酸根和铝离子发生配位作用在铝合金表面形成缓蚀膜。

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.