铝合金牺牲阳极极化性能研究

Polarization Performance of Two Aluminium Alloy Sacrificial Anodes

以两种Al-Zn-In-Mg-Ti系牺牲阳极为研究对象,采用开路电位、恒电流极化、循环伏安曲线、电化学阻抗等电化学测试方法,研究了牺牲阳极在不同电位下的极化性能。结果表明:阳极开路电位下由于氧化膜的存在导致阳极不易溶解,当对阳极施加外加电流后,双电层电容逐渐增大,极化电阻逐渐减小,氧化膜逐渐破裂;随着极化电位的增大,阳极发出电流迅速增大,此时极化电阻逐渐减小,最后基本稳定不变;极化电阻较小的阳极材料有着较好的电化学性能,这与4 d加速实验的评价结果相吻合。

The polarization performance of two kinds of Al-Zn-In-Mg-Ti sacrificial anodes at different potential was studied by open circuit potential, constant current test, cyclic voltammetry and electrochemical impedance spectroscopy. The results showed that the anodes were difficult to dissolve because of an oxide scale could form at open circuit potential. After an impressed current was applied to the anodes, the electric double layer capacitance gradually increased, the polarization resistance was gradually reduced, the oxide film gradually ruptured. With the increasing of polarization potential, the anode current increased rapidly, while the polarization resistance decreased and finally became stable. The anode with smaller polarization resistance exhibited a good electrochemical performance, which was consistent with the 4 d evaluation results by an accelerated test.