铝在三氯乙酸介质中的腐蚀动力学

Corrosion Kinetics of Aluminum in Trichloracetic Acid

采用失重法、极化曲线法和动力学分析,研究了铝在三氯乙酸(TCA)中的腐蚀行为,分析了TCA的浓度和温度对铝腐蚀速率的影响,导出了相应的动力学方程,求得了有关的动力学参数,测算出腐蚀电流密度和腐蚀电位等电化学参数,探讨了铝在TCA中的阳极溶解机理和阴极析氢机理。结果表明,在研究浓度范围内,铝在TCA中为匀速腐蚀,受活化控制;腐蚀速率与TCA浓度的关系遵循Mathur经验式,腐蚀速率和温度的关系符合Arrhenius公式;阴极和阳极反应动力学方程在理论和试验上一致;极化曲线法和失重法结果相吻合,腐蚀过程中铝表面无钝化层产生。

The methods of weight-loss, polarization curve and kinetic analysis were used to investigate the corrosion behavior of aluminum in trichloracetic acid （TCA） solutions. The influences of the concentration and temperature of TCA on the corrosion rate of aluminum were analyzed. The corrosion kinetic equation was formulated and the corresponding kinetic parameters were calculated. The corrosion potential and corrosion current density were tested. The mechanism of the anodic dissolution and cathodic hydrogen evolution on aluminum were discussed. The results indicated that the corrosion of aluminum showed an even rate and activation control in the studied concentration range. The relationship between corrosion temperature and rate followed Arrhenius formula, and the relationship between TCA concentration and corrosion rate followed Mathur formula. The theoretical and experimental kinetic equations of cathodic reaction and anodic reaction were consistent. The results of the polarization curves were in concordance with those of weight-loss tests. These results showed that there was no passivation layer on aluminum surface.