Cu杂质含量对Al-Zn-In系牺牲阳极性能的影响

为提高铝合金的阳极性能,采用电化学方法、电偶实验和电感耦合等离子体质谱,研究了不同Cu杂质含量的Al-Zn-In牺牲阳极在海水条件下的阳极性能.结果表明:铝合金牺牲阳极的Cu质量分数为0.005%时,阳极表面溶解均匀,工作电位处于-1.047!-1.068 V,电流效率达到93%以上,耦合电位较负且稳定,耦合电流适中,2 h时Al和Zn的溶解量分别为22和3.8μg/L,2和48 h时的扫描电流峰值分别为27和36"A,试样的耐蚀性增强;而Cu质量分数超过0.005%后,会限制In的活化作用,活性溶解阻力逐渐增大,随着Cu含量的增加电流效率明显下降.Cu质量分数0.005%的铝合金材料具有较好的阳极性能.

Effect of Cu impurity content on the anode characteristics of Al-Zn-In series sacrificial anode

To improve the anode performance of aluminum alloy anode, anode characteristics of Al-Zn-In sacrificial anodes with different Cu impurity content in the seawater were studied by electrochemical method, galvanic corrosion and ICP?MS. The results show that the sacrificial anode has good dissolution morphology by adding 0.005wt.% Cu. Its working potential is between -1.047~-1.068 V, and the current efficiency reaches 93%. The coupling potential is negative and stable and the coupling current is moderate. The dissolved amount of Al and Zn are 22 ppb and 3. 8 ppb at 2 h, and the current peak values of 2 h and 48 h are 27 mA and 36 mA. It means that the anti?corrosion property is enhanced. While the Cu content exceeds 0.005wt.%, with the increasing of Cu content, the resistance of active solution increases gradually, which indicates that the activation of In is limited. The current efficiency of anode decreases obviously. It is found that the aluminum alloy material owns better anode characteristics with 0.005wt.% Cu.