Study of Al-Zn-Cu-Sm Efficiency for Low-Voltage Sacrificial Anode Candidate

Abstract

Sacrificial anode is one of the most effective methods for preventing corrosion in seawater environment. Aluminum (Al) anode works very well in seawater environment with high electrochemical capacity and high driving voltage. Commonly used aluminum alloy sacrificial anodes have the possibilities to trigger the occurrence of Stress Corrosion Cracking and Hydrogen Embrittlement due to overprotection on high-strength steel. The low voltage sacrificial anode was developed to overcome this problem. Electrochemical behavior of Al-5Zn-0.5Cu alloy with varied samarium (Sm) addition of 0.02 wt% and 0.1 wt% was investigated in this study. The commonly used Al-5Zn-0.02In alloy is also tested as a comparison. Anode efficiency test with weight loss method according to DNVGL-RP-B401 standard was conducted to determine the performance of Al-5Zn-0.5Cu-xSm alloy. The addition of 0.1 wt% Samarium shows the best anode performance with electrochemical capacity 2809.80 Ah/kg and 98% efficiency. Al-5Zn-0.5Cu-0.1Sm alloy is the most potential alloy to be developed as a low potential sacrificial anode to replace commonly used aluminum sacrificial anode with indium addition.