AZ91D镁合金在NaCl溶液中的电化学噪声现象

Electrochemical noise of AZ91D magnesium alloy in sodium chloride solution

利用电化学噪声技术研究AZ91D镁合金的腐蚀过程,探讨Cl-浓度对AZ91D镁合金电化学噪声的影响.首先使用电化学工作站对有效噪声数据进行采集,然后对电化学噪声数据进行时域、频域分析,由此演化出电化学噪声特征参数,最终建立了电化学噪声与AZ91D镁合金腐蚀过程的联系.同时使用扫描电子显微镜观察了AZ91D镁合金出现电化学噪声时的表面形貌.实验结果表明,在含Cl-溶液中,AZ91D镁合金在一定时间内均出现不同程度的电化学噪声现象,同时,随着Cl-浓度增加,AZ91D表面伴随着点腐蚀.

The corrosion process of AZ91D magnesium had been investigated by electrochemical noise.The influence of Cl-concentration on electrochemical noise behavior of AZ91D magnesium had been discussed.The electrochemical system was used to collect noise data,and then analyzed using time-domain spectral and frequency-domain.According to the electrochemical noise character parameters,the relationship between electrochemical noise and the corrosion process of AZ91D magnesium was then established.Meanwhile,the morphology of AZ91D magnesium was observed by scanning electronic Microscopy（SEM） when the noise fluctuations had appeared on the alloy surface.The results show that AZ91D magnesium in the solution containing Cl-has the different electrochemical noise behaviors,and with the increasing of Cl-concentration,AZ91D magnesium surface has been appeared pitting corrosion.