Investigating the mechanical and electrical properties of hybrid joint of aluminum to copper obtained by friction stir welding and brazing

چکیده مقاله

In this study, friction stir welding (FSW) and brazing process of aluminum to copper were performed to investigate the mechanical and electrical properties of the joint. For this purpose, the brazing process was performed after FSW to fill the joint defects and create new bands in order to reduce the electrical resistance of the joint surface and increase the electrical conductivity. In order to investigate the mechanical properties of the joint, tensile and hardness tests were performed. The microstructure of the obtained samples was also examined by SEM and EDS analyses. The results show that the electrical resistance of the samples after the welding and brazing process has decreased from 0.45075 to 0.4502 Ω compared to the welded samples due to the low thickness of the transition layer at the interface of aluminum–copper and the formation of thin intermetallic layers. Moreover, the results of mechanical tests for welded and brazed samples indicated that the hardness of the joint increased by 28.5%, but the tensile strength decreased by 84.9%, because the presence of braze alloy between the aluminum and copper prevented the formation of an effective mechanical joint. Therefore, due to the increased electrical conductivity and reduced tensile strength, the obtained Al–Cu joint can be used in electrical industries.