Influence of Sn on Self-corrosion Potential of Multi-component Alloy AlMgZnSn_x

The influence of Sn on the self-corrosion potential and self-corrosion current density of multi-component alloy AlMgZnSnx was studied. An alloy ingot of 10 mm×60 mm was prepared under slagging protection condition in atmospheric environment. The electrochemical properties of the AlMgZnSnx alloy in 3.5% NaCl solution were investigated using electrochemical performance testing. The results showed that the self-corrosion potential did not change when a large number of tin was added into the AlMgZn alloy. The self-corrosion potential of the alloy was still lower than -1.37 V(vs.SCE) even if the weight percentage of the tin reached 95%. With the increase of tin content, the self-corrosion current density of the AlMgZnSnx alloy showed an increasing tendency first and decreasing afterward. The corrosion current density was in the order of magnitude between 10-3 to 10-5 A/cm2.