Microstructure and mechanical properties of friction stir welded dissimilar 5754-H111-6013-T6 aluminum alloy joints

Abstract

Abstract Aluminum alloys exhibit good strength, excellent corrosion resistance and good forming properties along with low specific density. Due to these superior properties, they are widely used in the automotive, chemical, and food industries, especially in shipbuilding and the yacht industry. It is important to join these alloys used in the mentioned industrial areas. However, it is very difficult to join Al and its alloys via traditional welding methods despite its widespread use. In this study, 5754-H111 and 6013-T6 aluminum alloys were joined by friction stir welding. Welding operations were carried out at 1250 rpm using welding feed rates of 12.5, 25, and 32 mm × min−1. Metallographic investigations were carried out to determine the microstructural and macrostructural properties of the weld zones. Tensile, bending, and hardness tests were also performed to determine the mechanical properties of the welded samples. The results obtained as a result of the tests were evaluated and interpreted. Micro-void defects were found to occur in the weld metal–HAZ transition zones. It was established that the welding speed affected the tensile strength. The highest tensile strength was obtained at a feed rate of 25 mm × min−1. It was determined that no cracking or fraction occurred in the welded samples as a result of the bending test.