Friction Stir Welding (FSW) is a solid-state welding process invented and patented by The Welding Institute(TWI) in 1991, for joining ferrous and non-ferrous materials. The FSW of Aluminium and its alloys has been commercialized; and recent interest is focused on joining dissimilar materials. However, in order to commercialize the process, research studies are required to characterize and establish process windows. This research work through material characterization of the welded joints establishes a process window for the Friction Stir Welding of 5754 aluminium alloy and C11000 Copper.