5A06铝镁合金海水腐蚀电化学特性

发布时间：2018-04-14 15:11

本文选题：A铝镁合金 + 海水腐蚀　；参考：《航空学报》2015年09期

【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。
[Abstract]:The electrochemical impedance spectra and polarization curves of 5A06 aluminum-magnesium alloy after corrosion at different time were measured by seawater corrosion test.The variation of impedance spectrum and polarization curve is qualitatively analyzed according to the microscopic morphology, and the equivalent circuit model is established. The values of each equivalent element are fitted by ZsimpWin, and the variation law of each equivalent element is quantitatively analyzed.On the other hand, the polarization curve epitaxy method is used to calculate the corrosion potential and current density after corrosion for different time, and the variation of instantaneous corrosion rate is obtained.The results show that the impedance spectrum of 5A06 aluminum-magnesium alloy without corrosion in seawater shows double capacitive arc resistance, and after one day of corrosion, the single capacitance impedance of 5A06 magnesium alloy increases first and then decreases with the prolongation of time.During the whole corrosion process, the corrosion current density and corrosion rate decreased first and then increased, and the corrosion potential of the sample increased in 1 day compared with that of the uncorroded sample, then decreased gradually, and finally showed an upward trend.
【作者单位】：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;
【基金】：国家自然科学基金(37689501)~~
【分类号】：TG174.3;V252.2

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