Experimental investigation on mechanical behavior of friction welded AL7075

Friction welding is widely used as a mass production method in various industries. In friction welding, the joints are formed in the solid state by utilizing the heat generated by friction. Friction welding can be used to join different types of ferrous metals and non-ferrous metals that cannot be welded by traditional welding processes. The process parameters such s friction pressure, forging pressure and rotating speed play the major role in determining the strength of the joints. In this work 7075 Aluminium alloy of 25.4mm diameter was taken as a test specimen. Friction welding was performed on the specimen with process parameters such as rotational speed of 1250 rpm, frictional pressure of 20 bar and forge pressure of 40 bar. Then the welded sample was subjected to annealing process at 650°C for 4 hrs. Later tensile, impact, hardness tests were performed on the specimen. These test results shows that welded sample has tensile strength of 362.88 N/mm², impact strength of 27 Joules and hardness of 23 HRB, which seems to be less when compared with parent metal. Based on the literature survey it is identified that a very fine molecular structure results decreased mechanical property.