Friction stir welding (FSW) provides users with many advantages over fusion welding techniques. Nevertheless, it is not widely employed in current industry mainly due to high equipment costs and royalties. To overcome these issues, a low-cost FSW technique operated at a right angle, called RAFSW, has recently been developed by our research team. To make the RAFSW technique reliable for potential users, we are going to analyze the effect of various post-weld heat treatments (PWHT) on the mechanical and physical properties of the RAFSW joints. To this end, optimized process parameters are used to weld butt joints of an AA6061-T6 alloy. The joints were characterized using a tensile test, a micro-hardness test, and metallography techniques. The most efficient aging time was obtained for various aging temperatures. Moreover, it was found that artificial aging at 220 °C for 30 min could be used as a fast and cost-effective artificial aging PWHT for the industrial sector. In addition, the repeatability of the PWHTs were demonstrated by studying the effect of waiting time prior to the artificial aging. Finally, it was revealed that a single fast artificial aging process is more beneficial than solubilizing followed by an artificial aging process in terms of tensile properties, consumed time, and cost.
In recent decades, friction stir welding (FSW) has attracted extensive attention of academic and industrial sectors as the most considerable development in metal joining processes. FSW lap joint is an interesting alternative for rivets, fusion welds and bonding particularly in the transportation industry. In this paper, the effect of tool design and process parameters on the generated downward axial force and strength of AA6061-T6 lap joints is studied. The welds are made by a low-cost friction stir welding technique at right angle (RAFSW). The studied tool design parameters are shoulder diameter, shoulder groove depth, pin length, pin angle, pin base diameter and pin lead. Moreover, the effect of tool rotational speed, traverse speed, plunge depth and lap joint configuration is evaluated. The Taguchi method is used to design the experiments and artificial neural network (ANN) modeling is applied to predict the plunging force and the strength of the joints. The results indicate that a quality weld can be obtained at low downward axial forces during welding by proper selection of tool design and process parameters. It is identified that one can achieve a quality lap joint at traverse speeds as high as 1400 mm/min and downward axial forces as low as 3.2 kN by a low-cost RAFSW technique.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.