Intergranular corrosion in AA5083 alloy: The influence of grain boundary segregation and its detection via TEM

The influence of grain boundary segregation on corrosion behaviour of AA5083 alloy remains unclear. In the present work, the segregation in both as-received and sensitized AA5083 alloys was examined via transmission electron microscopy (TEM). The influence of TEM specimen preparation methods on grain boundary segregation detection was explored. It is revealed that focussed ion beam (FIB) is reliable for the detection of grain boundary segregation. Further, the influence of grain boundary segregation on intergranular corrosion (IGC) of AA5083 alloy was examined. It is indicated that Mg segregation at grain boundary is decisive for IGC development in AA5083-H116 alloy, which also benefits IGC development in sensitized AA5083-H116 alloy by increasing the continuity of grain boundary micro-chemistry.