Microstructure evaluation of dissimilar AA2024 and AA7050 aluminum joints made by corner stationary-shoulder friction stir welding

Abstract Fillet welds made by the corner stationary-shoulder friction stir welding process between AA7050-T7451 and AA2024-T4 sheets were characterized using different metallographic techniques mechanical testing. Robotic of an aircraft’s skin-to-internal stiffeners examined Barker’s electrolytic Keller’s etching correlated with electron backscattered diffraction results energy-dispersive microprobe analysis. The composition grain orientation maps material flow lines demonstrated excellent weld quality in spite apparent inhomogeneities zone where mixing was complete. Welded joint efficiencies 85–92% base metals acceptable terms resistance to crack initiation propagation corrosion resistance, even softening heat-affected zones. It concluded that several optical microscopy are needed characterize these dissimilar aluminum fully post-weld thermal treatments could further improve their quality.