Experimental study on the effect of silver, nickel and chromium interlayers and upset pressure in joining SS304L-AA6063 alloys through direct drive friction welding process

Abstract

Joining of dissimilar alloys is demanded industrial applications and is effectively possible with the friction welding (FW) process. In this work, SS304L alloy rods were electroplated with silver (Ag), nickel (Ni) and chromium (Cr) and joined with AA6063 at various upset pressures (UP) (18, 21, 24 MPa) through friction welding process. The interlayer produced by the electroplating process was considered as the third element between AA6063 and SS304L during the FW. The results obtained through weld microstructures, fracture images, energy-dispersive X-ray spectroscopy, tensile properties, joint efficiency, Vickers microhardness and Charpy V-notch test of the fabricated dissimilar joints are discussed here. Fracture study showed the dimple fracture. The maximum strength and axial shortening were obtained as 216 ± 8 MPa and 27 mm, respectively. Maximum joint efficiency was achieved for Cr interlayer as 105 ± 4% at 24 MPa UP, which also showed a 1.79 tensile-to-yield (TS/YS) ratio. UP of 24 MPa improved ductile nature of joint. Ag and Ni joints rendered poor elongation. FW of chromium-electroplated specimen gave maximum weld performance than that of others. Ag interlayer at 18 MPa UP showed good hardness. Maximum impact energy observed by Cr at 24 MPa UP was 35 J. The novelty of the work is to frictionally weld the dissimilar metals of ϕ12 mm rods with Ag, Ni, Cr interlayer at welding pressures in view of safety and energy consumption. There were the changes in the microstructure and mechanical properties of joints when the interlayers, UPs changed.