In order to improve the service reliability of friction stir welded joints of high-strength aluminum alloy components for aviation and aerospace vehicles in corrosive environments

the stress corrosion behavior of 6 mm thick 6082–T6/7075–T6 dissimilar aluminum alloy friction stir welded joints treated with T6 was studied using metallographic analysis

electron microscopy analysis

and four-point bending stress corrosion method. The results showed that under the conditions of rotating speed 1200 r/min and weeding speed 80 mm/min

the 6082–T6/7075–T6 base material obtained a dense and well formed friction stir welded joint structure with an onion ring structure. The four-point bending stress corrosion of 6082–T6 and 7075–T6 base metal friction stir welded joints mainly occurs on the 7075–T6 aluminum alloy side on the retreating side

while the 6082–T6 aluminum alloy side on the advancing side shows good corrosion resistance. This is mainly due to the difference in electrode potential between dissimilar aluminum alloy base materials

which leads to galvanic corrosion of welded joints under stress. In addition

The formation of micro electric couples between the α–Al matrix and the second phase

as well as the presence of large angle grain boundaries in the TMAZ

HAZ

and BM regions of the welded joint

are also important reasons for stress corrosion.