因次分析法在电化学噪声分析中的应用

Application of Dimension Analysis in Electrochemical Noise Technique

采用电化学噪声技术,研究了铝合金2024-T3在NaCl溶液中孔蚀过程的电化学噪声特征.结果表明:电化学噪声的时域数据通过传统的FFT变换后得到的频域曲线SPD的特征参数(W、、k和f_c)均不能单独正确地刻画材料表面孔蚀的强度和趋势.基于因次分析法的基本原理和对材料腐蚀过程影响因素的分析,从电化学噪声频域曲线SPD的特征参数出发,导出了能正确表征材料表面孔蚀强度和趋势的两个参数S_E和S_G.其中,S_E正比于孔蚀的强度I_S,而S_G的意义仍在进一步的研究之中.

Pitting corrosion of aluminum alloy 2024-T3 in NaCl solution was studied using electrochemical noise technique. The spectral analysis results showed that the more positive the values of cut-off frequency(f(c)), the slope of high-frequency linear part of SPD (k) and white noise level(W) are, the more easily the pit initiates, but none of them can be used to depict the corrosion process individually. Two new parameters(S-E and S-G) were derived by using dimensional analysis method, and the value of S-E characterize the severity of pitting of corroding material. While the meaning of the other parameter(S-G) remains for further investigation.