中文摘要：

通过调整镀层厚度得到了具有不同孔隙率的Ni-P化学镀层。使用图形分析软件辅助贴滤纸法测得了镀层孔隙率,并研究了孔隙率对镀层电化学行为的影响,探讨了利用电化学测试对镀层孔隙率进行量化评价的方法。结果表明,图形分析软件可以提高贴滤纸法的准确性和可重复性,而电化学方法在测量镀层微小孔隙方面具有明显优势。极化曲线测试表明,孔隙率较小的镀层具有较高的腐蚀电位和较低的腐蚀电流密度,可根据所测曲线精确计算出镀层孔隙率。交流阻抗测试可进一步揭示孔隙率对镀层腐蚀机理的影响,存在孔隙的镀层其交流阻抗谱会表现双时间常数的特征,通过拟合所得电化学参数可以用来评价镀层孔隙率大小。

英文摘要：

Ni-P coatings with different porosities were prepared by changing coating thicknesses. Image analysis software was introduced to the neural chemical porosity tests to make the pore-counting process more reliable. The relationship between coating porosity and electrochemical behavior was investigated. Electrochemical meth- ods were used to evaluate the coating porosities. The results of polarization curve tests showed that the coatings with smaller porosities exhibited more positive corrosion potential and lower corrosion current density. Polariza- tion curve measurements can detect the existence of fin-pores in the coating more efficiently than the traditional chemical method. The results of EIS tests indicated that the coating with pores exhibited double-time constants of their impedance spectra after immersion into the corrosive solution for enough time. The coating resistance obtained by fitting the spectra with appropriate equivalent circuits is corresponded to the time constant of high frequency region and can be used to characterize the coating porosity.