Fabrication and Tribological Performance of Dissimilar Metal Joint Using Friction Stir Additive Manufacturing

In the present study, friction stir welding (FSW) is used to join different materials with distinct thermo-mechanical properties, such as copper (Cu) and aluminium (Al) 6061 alloy. The produced lap joint was characterized in terms of topographical, morphological, chemical, and mechanical characterization using the 3D profilometer, energy-dispersive spectroscopy (EDS), and field emission scanning electron microscopy (FESEM). 3D images show that there is no surface defect such as flushing during the fabrication of lap joint. The FESEM micrographs were taken at different magnifications. Weld nugget zone (WNZ) shows the mixing of Al and Cu and it produces a composite-like structure. The EDS spectra show the presence of elements such as Al, Cu, and oxides at the interface of two layers. Further, tribological results show that the average coefficient of friction value for weld zone, Cu plate, and Al plate are 0.125, 0.309, and 0.473, respectively. The weld zone shows an improvement in the frictional behaviour and COF value is reduced by 3.5 times compared to the Al alloy. The results indicate that FSW can be a promising route to joint dissimilar materials with enhanced properties.