Examination of the parameters effect on Al-Cu FSW welded butt joints using formability consent

Abstract

In most applications, joining aluminum to copper using friction stir welding (FSW) is a primary manufacturing process followed by secondary forming processes. The aim of this study is to investigate the effect of FSW process parameters (speed and feed rate) on the formability of Al-Cu joints.  Aluminum and copper blanks were welded at three different rotational speeds, i.e., 910, 1280, and 1700 rpm, and three different feed rates, i.e., 16, 29, and 44 mm/min. The base metals used in this study were aluminum (Al-1050) and copper in two states, i.e., as received and annealed. The mechanical properties of the base metals and the produced compounds were evaluated by tensile and hardness tests. The aluminum-copper joints were drawn into flangeless U-shape and cup shape using FSW to examine the formability of the joints. The maximum tensile load, punch load, and forming index were obtained when Al was at 1700 rpm and 16 mm/min, i.e., h. The welding was performed with annealed copper at the highest rotational speed and lowest feed rate due to work hardening of the joint. However, the ductility was highest at 1280 rpm and 44 mm/min, i.e., at medium rotation and highest travel speed. It can be depicted that when the FSW Al-Cu joint is further used in the forming process, moderate rotation and high feed speed should be adopted for welding to avoid work hardening and improve the ductility of the joint.