Evaluation of Optimal Conditions, Microstructure, and Mechanical Properties of Aluminum to Copper Joints Welded by FSW

The joining of dissimilar metals by Friction stir welding (FSW) is one of the newest metal joining processes. In this research, the tool was made from H۱۳ hot working steel, which has a concave shoulder with a ۳-degree inclined angle. The welding operation performed using a milling machine. The non-homogeneous workpieces joining of the Al alloy (۵۰۸۳) and a sheet of annealed copper (ASTM B۳۶) with a thickness of ۲ mm was investigated by the FSW method.  The joining process was carried out at three tool transverse speeds of ۲۵, ۳۵, and ۴۵ mm per minute and three rotational velocities of ۱۰۰۰, ۱۳۰۰, and ۱۶۰۰ rpm. Microstructural changes of the welded samples were analyzed by optical microscopy and scanning electron microscopy used to distinguish the type of phases. While its mechanical properties analyze according to different parameters used in the experiments. Also, the welded parts were subjected to microhardness and tensile tests. It found that the welding sample with a tool rotational speed of ۱,۳۰۰ rpm and a forward speed of ۳۵ mm/min has the best mechanical properties, with a tensile strength of ۸۲% and a yield strength of ۸۰% of aluminum base metal. While welded components with a forward speed of ۲۵ mm/min have tunnel defects and brittle phases of AlCu and Al۲Cu formed in the stir region so that with the increase of rotational speed and forward speeds, the percentage of these brittle phases increases.

کلیدواژه ها:

Non-homogeneous Metals ، Friction Stir Welding (FSW) ، Aluminum Series ۵xxx ، Copper Alloy ASTM B۳۶ ، Mechanical Properties