EFFECT OF CORROSION ON THE TENSILE PROPERTIES OF FRICTION-STIR WELDED AZ31B SHEET

摘要

To facilitate the use of magnesium and its alloys withinautomotive structures, it is necessary to characterize their possiblemechanical property degradation in typical applicationenvironments. This work examines the effect of exposure toNaCl-based corrosive environments on the mechanical propertiesof friction stir welded (FSW) AZ31B magnesium alloy sheet. Acomplete microstructural, electrochemical, residual stress andmechanical property characterization of the as-received FSWpanels was performed. Samples were subsequently exposed to0.01 M and 0.1 M NaCl solutions at the corrosion potential for 24h and any changes in mechanical properties, as a function ofexposure, to the corrosive environment monitored. Friction stirwelded panels exhibited large decreases in ductility compared tothe base AZ31B material. Exposure to 0.1 M NaCl for 24 hoursresulted in a degradation in mechanical properties for the basematerial, as well as the friction stir welded panel, whereas nosignificant changes were found for samples exposed to 0.01 MNaCl for 24 hours.