Electrochemical Performances of Recycled AZ31 Magnesium Alloy in NaCl Solution

Abstract

Recycled as-cast magnesium alloys were prepared by smelting method according to the nominal composition of AZ31 magnesium alloys. The structure and electrochemical properties of the recycled alloys were characterized and compared to those of the commercial as-cast AZ31 magnesium alloys. X-ray diffractometry patterns show that the main phases of the recycled alloy are α-Mg solid solutions and the recycled alloys present more Mg 17 Al 12 second phases than the commercialized alloy. Polarization curves results obtained from electrochemical experiments in 5% NaCl solution indicate that the recycled alloy exhibits a bit higher corrosion current density than the commercialized alloy and similar negative equilibrium potential to the commercialized alloy. The recycled alloy performs the higher corrosion rate in 5% NaCl solution and the worse corrosion resistance than the commercialized alloy according to self-corrosion rate and electrochemical impedance spectroscopy measurement results.