NaCl溶液中包覆铝层的LY12CZ铝合金阳极极化过程EIS特征  

EIS CHARACTERISTIC OF LY12CZ ALUMINIUM ALLOY WITH ALUMINIUM CLAD UNDER ANODIC POLARIZATION IN NaCl SOLUTION

作　　者：张正[1] 宋诗哲[1] 陶蕾[1] 

机构地区：[1]天津大学材料科学与工程学院,天津300072

出　　处：《中国腐蚀与防护学报》2008年第3期135-140,共6页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金项目(50499335)

摘　　要：用电化学阻抗谱(EIS)研究了LY12CZ铝合金及包覆铝层后LY12CZ铝合金在0.1 mol/L NaCl溶液中的腐蚀破坏过程,根据两种条件下铝合金在不同极化电位下的EIS特征,建立与之相应的电化学等效电路模型,并分析了腐蚀机理。研究表明,阳极极化过程中两种条件下铝合金的EIS主要特征类似,Nyquist图均呈现双容抗弧。在点蚀发展过程中,包覆铝层的LY12CZ铝合金的Nyquist图高,低频容抗弧半径增大,主要是因为包铝层与LY12CZ铝合金基体之间残存的氧化膜减缓了腐蚀的发展。The corrosion processes of LY12CZ aluminium alloy and Al clad LY12CZ alloy were studied by electrochemical impedance spectroscope （EIS） under anodic potential steps in 0.1 mol/L NaCl solution. According to the characteristics of EIS, the electrochemical equivalent circuit was established. The corrosion mechanisms of the aluminium alloys were further analyzed. The results showed that the EIS characteristics of LY12CZ aluminium alloy and Al clad LY12CZ alloy are similar during the corrosion processes. Their Nyquist plots both consist of two capacitive arcs. During the pitting propagation of Al clad LY12CZ alloy, the radius of capacitive arcs in Nyquist plot increased temporarily, because the oxide films between in LY12CZ and aluminium clad inhibited the pitting propagation.

关 键 词：电化学阻抗谱 LY12CZ铝合金 包铝层 

分 类 号：TG174.21[金属学及工艺—金属表面处理]