Influence of Ga and Bi on electrochemical performance of
Al-Zn-Sn sacrificial anodes
Al-Zn-Sn sacrificial anodes
(1. School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
2. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China)
2. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China)
Abstract: The influence of Ga and Bi on the microstructure and electrochemical performance of Al-7Zn-0.1Sn (mass fraction, %) sacrificial anodes was investigated by means of optical microscopy (OM), scanning electron microscopy/ energy dispersive X-ray analysis (SEM/EDAX) and electrochemical measurements. It was found that the coarse dendrites structure transformed into the equiaxed grains as well as a small amount of dendrite grains after adding Ga and Bi into Al-Zn-Sn alloys. A high current efficiency of 97% and even corrosion morphology were obtained for Al-7Zn-0.1Sn-0.015Ga-0.1Bi alloy. The results indicate that the proper amount of Ga and Bi is effective on improving the microstructure and electrochemical performance of Al-Zn-Sn alloy.
Key words: aluminium; sacrificial anode; electrochemical performance; electrochemical impedance spectroscopy; segregation