(1. 中南大学 化学化工学院，长沙 410083；2. 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用剥落腐蚀(Exfoliation corrosion, EXCO)实验和电化学阻抗测试方法，研究时效对新型含钪 Al-Cu-Li-Zr 合金剥蚀性能的影响。结果表明：合金在EXCO 溶液中剥落腐蚀敏感性由高到低的顺序为过时效，峰时效，欠时效；合金在EXCO溶液中浸泡初期，其电化学阻抗谱由一个高频容抗弧和低频感抗弧组成，且随浸泡时间的延长，低频感抗部分逐渐减弱直至消失；一旦发生剥蚀，合金的电化学阻抗谱出现两个部分重叠的容抗弧。依据腐蚀特征和电化学原理设计了等效电路图，对合金腐蚀发展过程的电化学阻抗谱进行了拟合，拟合数据和实验结果一致。
关键字: 含钪 Al-Cu-Li-Zr 合金；剥落腐蚀；电化学阻抗谱；时效
（1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of aging on the exfoliation corrosion (EXCO) susceptibility of a novel Al-Cu-Li-Zr alloy containing Sc were studied using EXCO tests and electrochemical impedance spectroscopy (EIS). The results show that the exfoliation susceptibility of the alloys in EXCO solution from high to low is as follows: over-aged alloy, peak-aged alloy and under-aged alloy. At early stage of immersion in EXCO solution, the EIS is comprised of a capacitive arc at high frequency and an inductive arc at low frequency, and the inductive component disappears with the increase of immersion time. Once exfoliation corrosion occurs, the EIS patterns are comprised of two overlapping capacitive arcs. The equivalent circuit was designed according to the characteristics of corrosion and the mechanism of electrochemical corrosion, and all EIS patterns were simulated after the appearance of two capacitive arcs, and the good agreement between the experiment results and the simulated results is obtained.
Key words: Al-Cu-Li-Zr alloy containing Sc; exfoliation corrosion; electrochemical impedance spectroscopy (EIS); aging treatment
