Comparison of the Microstructure and Mechanical Behavior of the Welding Zone of Aluminum Alloy 5754 by FSW and TIG Methods

In this research, the weld zones resulting from friction stir welding (FSW) and arc welding with shielding gas and non-consumable tungsten electrodes (TIG) on AL-5754 alloy were compared. The input parameters for both processes were selected based on the Taguchi method, and the welding operations were performed accordingly. To achieve optimal input parameters, tensile, ultrasonic, and hardness tests were conducted on the samples. The results indicated that the weld created by the TIG method exhibited higher tensile strength for samples 3, 4, and 9, with values of 195, 152, and 151 MPa, respectively. However, in FSW, the finer granularity of the base material (44 microns) resulted in a better microstructure (30 microns) compared to the TIG method. This characteristic leads to enhanced mechanical properties, such as toughness, fatigue strength, and flexibility, in the FSW method. Since the hard work done on the base metal is lost with this method, and there is no possibility of increasing the strength of the weld, as can be done with the TIG method by changing the filler material, the TIG method is preferred in this comparison.