Effects of precipitates on the electrochemical performance of Al sacrificial anode

The influence of precipitates on the electrochemical performance of Al-Zn-In-Mg-Ti-Si sacrificial anode was investigated by the TEM observation and electrochemical measurements. The results indicate that the shape and size of precipitates in the alloys has great impact on the electrochemical performance. The anodes with rod-like precipitates are easily corroded along grain boundaries, resulting in the low current efficiency caused by serious grain loss. In comparison, the anodes with spherical or discal precipitates have high current efficiency and even corrosion morphology. The precipitates with a size of about 400 nm are conducive to improve the electrochemical performance of anodes. (C) 2011 Elsevier Ltd. All rights reserved.