通过对表面带有硫酸阳极化膜和H06-1012H航空环氧底漆的L Y12CZ铝合金型材进行剥蚀敏感性加速腐蚀试验(EXCO)，采用时域法Laplace转换EIS和截面 金相观察来 衡量铝合金的膜下腐蚀.结果表明：时域法EIS测出的试样Rd、Cg能够评估膜下 腐蚀的损伤程度；不同膜下腐蚀形态对应着不同的Rd、Cg的范围.Rd和 Cg随腐蚀时间的变化趋势可以反映基体金属点蚀的萌生、漆膜鼓泡和基体出现剥蚀的 历程.大量平行数据的统计分析表明：logRd符合Gumbel分布，logCg符合正态 分布；由于logRd服从Gumbel分布，故可以根据小面积试样的logRd值，对大面 积试样腐蚀最严重处的状况有所估计.大面积试样在EXCO溶液中浸泡时，其logRd随 时间呈指数下降.
In this article,EIS by Laplace transform time domai n method was used to evaluate under-film corrosion of coated 2024T3 aluminum all oy.EXCO immersion test,optical microscope observation and statistic method were also employed. Results show that EIS by time domain method is a quick,nondestructive and quanti tative method to detect under-film corrosion of 2024T3 Al alloy.The low frequenc y impedance (Rd),high frequency capacitance (Cg) can be treated as i ndicators of under-film corrosion.Correlation was established between Rd a nd Cg and corrosion states.Statistical analysis show that log(Rd) ma tch Gumbel distribution and log(Cg) correspond to normal distribution. Investigations show that different corrosion states have different dynamic rules .If only pitting occurs on the specimen,Rd and Cg fluctuates.When th e exfoliation happens,Rd will decrease and Cg will increase with tim e.Log(Rd),which reflect the most severe corrosion in large-scale specimen, will decrease exponentially with time in EXCO solution.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%