采用原位电化学阻抗(EIS)技术研究了薄液膜条件下β相对镁铝合金初期腐蚀行为的影响。结果表明由NaCl诱发的镁合金初期大气腐蚀, β相起到了关键作用。在早期的10 h内, β相体积分数较多的镁合金对应阻抗谱的电荷转移电阻比较大, 表明其腐蚀速率较慢, 这是由于镁合金中β相相对耐蚀。但在高浓度Cl-作用下, 随暴露时间的延长, 一旦突破合金表面β相的阻碍后电荷转移电阻明显下降, 腐蚀速率加快。β相体积分数较少的镁合金随着暴露时间的延长, 腐蚀产物膜的保护性明显优于β体积分数较多的镁合金, 这有助于减缓β相体积分数较少的镁合金基体在暴露后期的腐蚀速率。
The in-situ electrochemical impedance spectrum measurements were conducted to investigate the early stage of the atmospheric corrosion behavior of the magnesium alloys with different volume fractions of β phase. The results indicated that β phase played a key role in the course of atmospheric corrosion of the magnesium alloys that was induced by NaCl particles centralized in the early time period. During the early ten hours the magnesium alloys with high volume fraction β phase had a bigger chargetransfer resistance, showing a better corrosion resistance. This phenomenon could be attributed to the better corrosion resistance of β phase. However, a faster corrosion occurred for the magnesium alloys with high volume fraction β after ten hours when the β phases were broken and the charge-transfer resistance dropped dramatically due to the high concentration of Cl−. As the exposure time prolonged, the protective function of the corrosion product films in Mg–3Al alloy was significantly better than those in the other two alloys as they helped slow down the corrosion rate of magnesium alloys with less volume fraction β phase.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | WANG Jun, HAN Wei, LI Hongxi, WANG Zhenyao, Review on electrochemical methods for atmospheric corrosion research, Corrosion Science and Protection Technology, 14(6), 334(2002)[2](汪 俊, 韩 薇, 李洪锡, 王振尧,大气腐蚀电化学研究方法现状, 腐蚀科学与防护技术, 14(6), 334(2002))[3]K.Darowicki, Corrosion rate measurements by non-linear electrochemical impedance spectroscopy, Corrosion Science, 37(6), 913(1995)[4] K.Darowicki, S.Krakowiak, P.Slepski, Evaluation of pitting corrosion by means of dynamic electrochemical impedance spectroscopy, Electrochimica Acta, 49, 2909(2004) [5]S.Krakowiak, K.arowicki, P.Slepski, Impendance of metastable pitting corrosion, Journal of Electronalytical Chemistry, 33, 575(2005)[6] K.Darowicki, S.Krakowiak, P.Slepski, The time dependence of pit creation impedance spectra, Elecrochemistry Communications, 6, 860(2004)[7] D.Li, Y.Hu, B.L.Guo, Study on the evaluation of localized corrosion of 2024T3 aluminum alloy with EIS, Materials Science Engineering A, 280, 173(2000)[8]A.Nashikata, Y.Yamashita, H.Katayama, T.Tsuru, A.Usami, K.Tanabe, H.Mabuchi, An electrochemical impendence study on atmospheric corrosion of steels in a cycle wet-dry condition, Corrosion Science, 37(12), 2059(1995)[9]A.Nashikata, Y.Ichihara, T.Tsuru, An application of electrochemical impendence spectroscopy to atmospheric corrosion study, Corrosion Science, 37(6), 897(1995)[10] R.P.Vera Crue, A.Nashikata, T.Tsuru, AC impendence monitoring of pitting corrosion of stainless steel under a wet-dry cyclic condition in chloride-containing environment, Corrosion Science, 38, 1397(1996)[11] A.Nashikata, Y.Ichihara, T.Tsuru, Electrochemical impedance spectroscopy of metals covered with a thin electrolyte layer, Electrochimica Acta, 41, 1057(1996)[12] Y.L.Cheng, Z.Zhang, F.H.Cao, J.F.Li, J.Q.Zhang, J.M.Wang, C.C.Nan, A study of the corrosion of aluminum alloy 2024&ndash |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%