Effects Of Alloy Elements On Corrosion And Electrochemical Properties Of Magnesium Anode

Abstract:In this paper,the effect of alloy elements on the corrosion and electrochemical properties of AZ61magnesium alloy were studied.The corrosion and electrochemical properties of magnesium anode were measured by H2evolution,galvanostatic discharging curves,dynamic potential measurement et al. A new environmental friendly magnesium anode is designed,which has better comprehensive performance compared with AP65and AZ61. The main conclusions are as follows:(1) At25℃and in3.5%NaCl media,Er,Nd,Ga,Be can improve the corrosion resistance of AZ61.while the addition of Sn could increase the H2evolution rate of AZ61.The ability of improving corrosion resistance of AZ61is Er>Nd>Be>Ga>Sn.(2) Magnesium anode that contains Sn provides the most negative electrode potential.While other alloy elements(Er,Nd,Ga,Be) can hardly influence the discharge behaviors of AZ61. The electrochemical properties of AZ61-Sn as a anode material are comparatively better.(3)At25℃and in3.5%NaCl media, Er,Nd,Ga can reduce the H2evolution rate of AZ61-Sn.And both of them have little effect on the discharge behaviors of AZ61-Sn.The corrosion and electrochemical properties of Mg-Al-Zn-Sn-Er are better than others, it can be used as a environmental friendly magnesium anode(4)When the anodic current density is50mA/cm2,AP65can provide the most negative potential which is-1.652V.The potential of Mg-Al-Zn-Sn-Er is-1.558V.And the most positive potential is-1.518V,which belongs to AZ61.While the corrosion resistance of magnesium alloy is Mg-Al-Zn-Sn-Er>AZ61>AP65.Compared with AZ61and AP65, the utilization efficiency of Mg-Al-Zn-Sn-Er is much higher.Thus,it has better comprehensive performance.(5)From the EIS,we can know that the electrochemical activities of magnesium anodes are AZ61-Sn>AZ61-Sn-Er>AZ61>AZ61-Er.while the corrosion resistance of magnesium anodes is AZ61-Er>AZ61-Sn-Er>AZ61>AZ61-Sn.The corrosion and electrochemical properties of AZ61-Sn-Er are comparatively better.(6)Mg-Al-Zn-Sn-Er alloy has such good performance due to the alloy element Sn and Er.Sn is an effective element that can improve the corrosion voltage of AZ61. Er can intensively influence the microstructure of AZ61.