INVESTIGATION OF MICROSTUCTURAL AND MECHANICAL PROPERTIES OF FRICTION STIR WELDED Cu/Al-1050 BUTT JOINT

In this study, the weldability of pure copper (cu) plate to aluminum (al-1050) plate has been nvestigated at a constant tool rotation speed of 515 rpm and different weld speeds by friction stir welding. while a relatively sound cu/al-1050 joint was achieved at the lowest weld speed (12 mm min^-1), very poor joints were obtained at the higher weld speeds (30 and 50 mm min^-1). therefore in this study, microstructural characterization and mechanical properties of the joint at weld speed of 12 mm min^-1 were evaluated. microstructure investigations by optical microscope and scanning electron microscope, energy-dispersive x-ray spectroscopy (eds), x-ray diffraction (xrd), tensile test and microhardness measurements were carried out in this joint. microstructure inspections and eds analysis revealed that the stir zone of the joint consisted of aluminum-rich and copper-rich structures. alcu, al2cu3, alcu4 and al4cu9 intermetallic compounds were detected in the weld region by xrd. volume fraction of copper-rich phases in the stir zone was calculated by image analysis software which is approximately 32%. tensile test results show that the tensile strength of cu/al-1050 joint lower 50% and 24% than that of cu base metal and al-1050 base metal, respectively. it was observed that hardness’s in the stir zone increased when compared to the base metals and varied between 74 hv and 280 hv.