Joining of AA 6061/Ti–6Al–4V with zinc interlayer using friction welding process

The formation of intermetallic phases consisting of intermetallic compounds during welding of aluminium/titanium joints is a challenge to the welding processes, in the last two decades. Friction welding is attempted to reduce the formation of intermetallic phases through inserting the interlayer material. In recent years, the number of approaches has been used to insert the interlayer material to avoid metallurgical phases at the weld interface. In this paper, the new technique of electrodeposited zinc coating on titanium substrate acted as an interlayer. Different welding joints were made by varying the interlayer thickness, and henceforth, the characterization is almost done against the mechanical and microstructure of the weld interface. The result shows that the specimen joint having 5 µm Zn interlayer has higher mechanical strength when compared to the specimen joints having 2 µm and 3 µm Zn interlayer. The results of the EDAX line scan concentration profile reveal that across the joint interface there is diffusion of the zinc interlayer into the aluminium zone. The microstructural investigation has been carried out at the joint interface of titanium and aluminium alloy with zinc as an interlayer. It is revealed that the formation of the thin interfacial reaction layer occurs in between the zinc and titanium zone. The intermetallic compounds are formed here in this region, and they are identified as secondary phases of the reaction between zinc and titanium.