微区电化学技术在薄液膜大气腐蚀中的应用

Application of micro-electrochemical technologies in atmospheric corrosion of thin electrolyte layer

薄液膜大气腐蚀的本质是吸附于金属基体表面的水汽形成薄电解质液膜引起的金属腐蚀现象.由于液膜很薄,无法满足常规的三电极溶液测试体系要求,使得微区电化学技术在该领域得到广泛的应用.本文对比分析了用于薄液膜大气腐蚀的电化学测试技术,着重介绍了扫描Kelvin探针、丝束电极、微液滴电极等测试方法在薄液膜大气腐蚀研究中的应用,并通过总结测试中涉及的关键参数揭示了薄液膜/液滴尺寸与腐蚀动力学过程的关系.最后提出了微区电化学方法在该领域应用目前存在的问题以及今后可进一步提升的可能.

The atmospheric corrosion of a metal under a thin electrolyte layer is caused due to the adsorption of the thin electrolyte layer on metal surfaces. As the electrolyte layer is considerably thin,the application of a traditional three-electrode system is considerably difficult; therefore,localized electrochemical technologies are of great use in this field. Herein,different localized electrochemical techniques for atmospheric corrosion under a thin liquid film were discussed. In particular,the applications of scanning Kelvin probe microscopy,wire-beam electrodes,and micro-droplet electrodes were introduced and comprehensively explained. In addition,the key parameters of the tests,which show the relation between thin film/droplet size and corrosion kinetics,were summarized. Furthermore,the issues that currently exist in this field and the potential for improvement was proposed in this research.