(1. 中南大學 化學化工學院，長沙 410083；2. 中南大學 材料科學與工程學院，長沙 410083)
摘 要: 采用剝落腐蝕(Exfoliation corrosion, EXCO)實驗和電化學阻抗測試方法，研究時效對新型含鈧 Al-Cu-Li-Zr 合金剝蝕性能的影響。結果表明：合金在EXCO 溶液中剝落腐蝕敏感性由高到低的順序為過時效，峰時效，欠時效；合金在EXCO溶液中浸泡初期，其電化學阻抗譜由一個高頻容抗弧和低頻感抗弧組成，且隨浸泡時間的延長，低頻感抗部分逐漸減弱直至消失；一旦發(fā)生剝蝕，合金的電化學阻抗譜出現(xiàn)兩個部分重疊的容抗弧。依據(jù)腐蝕特征和電化學原理設計了等效電路圖，對合金腐蝕發(fā)展過程的電化學阻抗譜進行了擬合，擬合數(shù)據(jù)和實驗結果一致。
關鍵字: 含鈧 Al-Cu-Li-Zr 合金；剝落腐蝕；電化學阻抗譜；時效
（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
