Study on Corrosion Behavior of Friction Stir Welded Joints of AA5052 Aluminum/AZ31B Magnesium Alloys

In this work,the friction stir welding was used to weld the Al / Mg alloy joints with good appearance. In order to study the corrosion behavior and corrosion mechanism,based on the analysis of the microstructure of the welded joint,the corrosion behavior of the welded joint was monitored and analyzed by the neutral salt spray corrosion test and electrochemical test,and the corrosion weight loss of the welded joint was analyzed. The results show that the inhomogeneity of the distribution of Al-Mg intermetallic compound and β phase in magnesium alloy in the stir zone and the thermo-mechanically affected zone,as well as the difference in the grain size of the region,leads to the difference in the tendency of forming primary batteries in the micro-plot of stirring zone and thermo-mechanically affected zone,thus showing the difference in corrosion morphology and corrosion behavior. The occurrence of galvanic corrosion leads to high corrosion current density in the welded joint,and the corrosion resistance is inferior to the base metal. During the whole neutral salt spray corrosion process,the mass loss is gradually increased,and the corrosion rate shows a downward trend after the first rise. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.