Effect of friction welding condition on joining phenomena, tensile strength, and bend ductility of friction welded joint between pure aluminium and AISI 304 stainless steel

Abstract

Aluminium (Al) and stainless steel have such some advantages as high functionalities for the industrial usage. However, the dissimilar joints have severe problems such as generating the intermediate layer consisting of a brittle intermetallic compound (IMC interlayer) during welding process. Friction welding is very useful for making of dissimilar joint. This paper described the effect of friction welding condition on joining phenomena, tensile strength, and bend ductility of friction welded joints between pure Al (CP-Al) and austenitic stainless steel (AISI 304). The joining phenomena during the friction process such as joining behaviour, friction torque, temperature changes at the weld interface, and transitional changes of the weld interface were investigated. The effects of friction time and forge pressure on the tensile strength and bend ductility of joints were also investigated, and the metallurgical characteristics of those were observed. The joint, which had high joint efficiency, the fracture on the CP-Al side with no crack at the weld interface, and no IMC interlayer on the weld interface, could be successfully achieved. Then, the joint should be made with a high forge pressure of 150MPa, the opportune friction time at which the temperature on the weld interface reached about 573K or higher, and those friction welding conditions were suggested for obtaining good joints with high joint efficiency and the bend ductility of 90°.