Mg对Al-Zn-Sn阳极合金组织与电化学性能的影响

Effects of Mg on microstructure and electrochemical properties of Al-Zn-Sn anode alloys

为提高Al-7Zn-0.1Sn(质量分数,%)牺牲阳极的电化学性能,采用扫描电镜(SEM)、透射电镜(TEM)、动电位极化、电化学阻抗等方法,研究了不同含量的Mg对Al-7Zn-0.1Sn合金微观组织和电化学性能的影响。结果表明:Mg可使Al-7Zn-0.1Sn合金从粗大枝状晶向等轴晶转变;适量Mg可改善Al-7Zn-0.1Sn合金的电化学性能;随着Mg含量增加,合金电位负移、电流效率逐步提高;当Mg含量为2%时,合金具有最好的综合电化学性能。

Influence of Mg on microstructure and electrochemical properties of Al-7Zn-0. 1Sn( mass%) alloy was investigated by means of scanning electron microscopy( SEM),transmission electron microscopy( TEM),potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that the coarse dendrites structure is transformed into the equiaxed grains after adding Mg into the Al-Zn-Sn alloys. Proper Mg addition is effective on improving the electrochemical properties of Al-7Zn-0. 1Sn alloy. The corrosion potential is shifted negatively and the current efficiency is increased for the alloys with the increasing of Mg content. The optimal electrochemical properties can be obtained when the Mg content in the alloy is 2 mass%.