物理化学学报2012，Vol.28Issue(9)：2097-2107,11.DOI:10.3866/PKU.WHXB201206251
基于电化学噪声研究缓蚀剂对AA6063铝合金点蚀的影响
Effect of Inhibitors on Pitting Corrosion of AA6063 Aluminium Alloy Based on Electrochemical Noise
摘要
Abstract
The pitting corrosion of AA6063 aluminum alloy in 3% (w) NaCI solution was investigated by electrochemical noise (ECN), electrochemical impedance spectroscopy (EIS), and polarization curves. Inhibition of nucleation and propagation of metastable pits by inhibitors, such as CeCI3, Na2CrO4, and 8-hydroxyquinoline (8-HQ), was evaluated based on ECN data statistics. It was found that the local pH could be over 8.4 near the cathode phase (Al-Si-Fe) due to dissolution of Al matrix, leading to preferential deposition of Ce(OH)3 on the surface of the cathode phase, thereby inhibiting the cathodic process of pitting corrosion. The average electric charge (q) of metastable pits decreased with increasing the corrosion inhibitor concentration, but the average lifespan of noise transients remained almost constant, indicating that Ce3+ ions did not accelerate the rehabilitation of metastable pits directly, but reduced the dissolution rate of Al inside active pits. However, CrO42- ions not only accelerated the rehabilitation of metastable pits, but also reduced the nucleation rate of the AA6063 aluminum alloy. In contrast, 8-HQ acted as an effective corrosion inhibitor for AA6063 aluminum alloy through formation of insoluble chelate films with Al3+ ions and Mg2+ ions, but failed to enhance the pitting corrosion resistance of the aluminum alloy.关键词
铝合金/电化学噪声/点蚀/缓蚀剂/形核速率Key words
Aluminium alloy/ Electrochemical noise/ Pitting corrosion/ Inhibitor/ Nucleation rate分类
化学化工引用本文复制引用
阮红梅,董泽华,石维,陈东初..基于电化学噪声研究缓蚀剂对AA6063铝合金点蚀的影响[J].物理化学学报,2012,28(9):2097-2107,11.基金项目
教育部科学技术研究重点项目(211129)资助 （211129）
