FRICTION STIR BUTT WELDABILITY OF DISSIMILAR ALLOYS AA5754 AND AA1050

The main objective of this study was to assemble by friction stir welding two dissimilar sheets made with AA5754 Al-Mg alloy and AA 1050 aluminum, which are intensely used in the automotive industry. The applied welding speed was 75mm/min with different tool rotational speeds (780, 1330 and 2440rpm). The mechanical properties and the microstructure of the welded joint were investigated by the tensile test, the three-point bending test, the microhardness measurements, the optical microscopy, scanning electron microscopy and energy dispersion spectrometry (EDS). The main zones were observed in the welded joint. Optimum mixing was achieved during the assembly process with a welding tool rotation speed of 2440rpm. It was determined that the microstructures formed had a significant effect on the hardness and tensile strength of welded dissimilar materials such as the precipitated phases in the nugget zone. The best result in terms of tensile strength was obtained at 780rpm with 80% performance.