Effect of friction stir welding parameters on the mechanical properties and microstructure of the dissimilar Al5083-copper butt joint

In this paper, butt joining of Al5083 to commercially pure copper by friction stir welding method has been investigated. The effect of welding parameters, rotational speed of the tool and tool offset on joint strength and microstructure have been studied experimentally. By examining different situations, joint strength was optimized in terms of rotational speed and offset. Results show that tool offset to the copper side reduces defects and increases the joint strength. Welded joint that was conducted at the rotation speed of 800r/min, tool traverse speed of 40mm min(-1) and 1mm offset to the copper side had the highest tensile strength, about 96% of the weak base metal strength. Microstructure in the stir zone had different morphology from that observed in the base metal. The analyses were performed in intermetallic compounds formed in this area. Al4Cu9 and Al2Cu, were the intermetallic compounds detected in stir zone.