航空学报 > 2015, Vol. 36 Issue (9): 3147-3154   doi: 10.7527/S1000-6893.2014.0305

5A06铝镁合金海水腐蚀电化学特性

张艾艾, 何晶靖, 刘天娇, 张卫方   

  1. 北京航空航天大学 可靠性与环境工程技术(国防科技)重点实验室, 北京 100191
  • 收稿日期:2014-08-11 修回日期:2014-10-28 出版日期:2015-09-15 发布日期:2014-11-29
  • 通讯作者: 何晶靖 女, 博士, 副教授。主要研究方向: 结构健康监测/失效物理。 Tel: 010-82314879 E-mail: 09722@buaa.edu.cn E-mail:09722@buaa.edu.cn
  • 作者简介:张艾艾 女, 硕士研究生。主要研究方向: 失效物理。 Tel: 010-82314879 E-mail: aiai0324@126.com
  • 基金资助:

    国家自然科学基金 (37689501)

Electrochemical features of corrosion of 5A06 Al-Mg alloy in seawater

ZHANG Aiai, HE Jingjing, LIU Tianjiao, ZHANG Weifang   

  1. Science & Technology Laboratory on Reliability & Environmental Engineering, Beihang University, Beijing 100191, China
  • Received:2014-08-11 Revised:2014-10-28 Online:2015-09-15 Published:2014-11-29
  • Supported by:

    National Natural Science Foundation of China (37689501)

摘要:

对5A06铝镁合金进行海水腐蚀实验,测试腐蚀不同时间后的电化学阻抗谱和极化曲线。结合微观形貌,定性分析阻抗谱和极化曲线的变化规律;进而建立等效电路模型,并采用ZsimpWin拟合给出各等效元件的值,定量分析其变化规律。另一方面,利用极化曲线外延法计算腐蚀不同时间后的自腐蚀电位和自腐蚀电流密度,从而得到瞬时腐蚀速率的变化规律。结果表明:没有经过腐蚀的5A06铝镁合金在海水中的阻抗谱呈现双容抗弧特征;腐蚀1天后,随时间的延长,单一容抗弧呈现出先增大后减小的趋势。在整个腐蚀过程中,自腐蚀电流密度和腐蚀速率先减小后增大;腐蚀1天相对未经腐蚀的样品腐蚀电位(Ecorr)有所升高,随后逐渐下降,最终又呈现上升的趋势。

关键词: 5A06铝镁合金, 海水腐蚀, 电化学阻抗谱, 极化曲线, 腐蚀速率

Abstract:

A corrosion experiment of 5A06 Al-Mg alloy immersed in seawater is conducted. The electrochemical impedance spectra and polarization curves for different periods are tested. Combining the microstructure, analyze the changing of these impendence spectra and polarization curves qualitatively. Three different equivalent circuits are proposed and the values of each equivalence element are fitted using the software of ZsimpWin based on a suitable equivalent circuit. Then the change rules are quantified. At the same time self-corrosion electric potential and self-corrosion electric current density are obtained by extend curve of polarization curves, which reflects the change of the instantaneous corrosion rate. The results show that double capacitive reactance arcs have appeared for a fresh 5A06 Al-Mg alloy. When the alloy is corroded for more than one day, the capacitive reactance arc is increased and then decreased as the immersion time is prolonged. The self-corrosion electric current density and the instantaneous corrosion rate are decreased and then increased. The Ecorr increases when it is corroded for one day, then gradually declines and ultimately presents the rising trend.

Key words: 5A06 Al-Mg alloy, corrosion in seawater, electrochemical impendence spectroscopy (EIS), polarization curves, rate of corrosion

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