Torsion Strength of Dissimilar Metals Friction Weld Joint of A6061-St41 Round Bar with Various One-Sided Chamfer Angle and Burn-Off Length

Abstract

This paper reports the torsion strength of dissimilar metals friction welded aluminum alloys A6061 and mild steel St41 round bar affected by various one-sided chamfer angle and burn-off length. In this study, cylinder specimens were made of aluminum alloy A6061 and mild steel St41. On the contact area of stationary specimens, chamfer angle of 30, 45, 60, and 90 degrees or no chamfer with chamfer length of 5 mm and 18 mm diameter were machined. Continuous drive friction welding was performed with the revolution speed of 1600 rpm, initial compressive force of 7 kN, and burn-off the length of 10, 15, and 20 mm, then upset compressive force of 14 kN was applied on the specimen for 40 seconds. Torsion strength of the specimens was conducted based on the ASTM standard. Macrostructure observation and microhardness testing were also done on the friction weld joint. From the results, it was found that maximum torsion strength occurred in the specimen of dissimilar metal A6061 & mild steel St41 friction weld with chamfer angle of 30 degrees and burn-off length of 15 mm and fractured in aluminum alloy part. It may occur due to the complete cone geometry, minimum porosity, and adequate total burn-off length in the specimen.