Effects of the FSW Parameters on Microstructure and Electrical Properties in Al 6061-T6- Cu C11000 Plate Joints

Friction Stir Welding (FSW) is a feasible welding process to join dissimilar materials due to its solid-state nature. In this study the FSW of 6061-T6 aluminum with pure Cu plates was performed with the objective of evaluating the effects of the FSW parameters on the microstructure and electrical properties. The processing parameters (rotational and traverse speeds) were established to reduce the common defects in the friction-stir welding process. Therefore, the obtained results validated the better mechanical properties and a smaller increase of the electrical resistivity. The rotational speeds used were of 1000, 1150, and 1300 rpm, and the traverse speeds of 20, 40, and 60 mm/min, with the purpose of varying the heat input of the process. The microstructural characterization revealed the presence of a mixture of aluminum and copper into the weld zone, along with copper particles and the formation of intermetallic compounds. It was found that the electrical resistivity of the joints ranged from 0.029 to 0.036 μΩ. The highest electrical resistivity values were obtained at the lowest traverse speed (20 mm/min) and the lowest resistivity values were obtained at highest traverse speed (60 mm/min).