Friction Stir Welding (FSW) is a solid-state welding process that has multiple advantages over fusion welding. The design of tools for the FSW process is a factor of interest, considering its fundamental role in obtaining sound welds. There are some commercially available alternatives for FSW tools, but unlike conventional fusion welding consumables, their use is limited to very specific conditions. In this work, equations to act as guidelines in the design process for FSW tools are proposed for the 2XXX, 5XXX, 6XXX, and 7XXX aluminum series and any given thickness to determine: pin length, pin diameter, and shoulder diameter. Over 80 sources and 200 tests were used and detailed to generate these expressions. As a verification approach, successful welds by authors outside the scope of the original review and the tools used were evaluated under this development and used as case studies or verification for the guidelines. Variations between designs made using the guidelines and those reported by other researchers remain under 21%.

Sustainability scores can be used to assess manufacturing strategies, going one step beyond a standard economic assessment. This work uses a previously proposed methodology to evaluate two of the most common welding processes for aluminium alloys that are specifically used in the fabrication of components for the transport industry based on their advantages in generating lightweight and dimensionally efficient parts. For comparison and as proof of concept, two welding methods were selected: Friction Stir Welding (FSW) and Gas Tungsten Arc Welding (GTAW). FSW attained a higher overall sustainability score. Values were calculated for an existing aluminium product, which was part of the opening and closing system of an electric train door, and the final score was 0.78 from FSW compared to 0.69 from GTAW, which was 11% higher in FSW compared to the conventional arc welding process. The analysis carried out included economic, physical, social, and environmental impacts. Finally, an example pertinent to a current EV component is described and considered along with a plan to determine the best welding process for a particular application, and with the calculations, the score obtained for GTAW was 0.43 and 0.68 for FSW, which was 36% higher that the result for the conventional arc welding process.

Dissimilar aluminum joints have widespread applications across various industries, including the electronics and automotive sectors, owing to their unique combination of advantages, including reduced density and enhanced mechanical properties. These characteristics make them an innovative solution for multi-material processing challenges presented in the engineering industry. This article focuses on Friction Stir-Welded butt joints made using a weld–flip–weld approach between aluminum AA6061-T6 and pure copper C11000, exploring the effects of varying rotational speeds (1000, 1200, and 1400 RPM), offsets (0 and 1 mm) in the joint soundness, mechanical strength, and electrical conductivity. The welds were evaluated using non-destructive testing with phased-array ultrasound and tensile testing. Additionally, the electrical conductivity was measured to assess their response to electrical currents. The findings reveal a significant correlation between joint efficiency and electrical conductivity, with the highest values corresponding to a weld executed with a rotational speed of 1400 rpm, traverse speed of 40 mm/min, and 1 mm offset towards the aluminum, achieving the highest joint efficiency, reaching a joint efficiency of approximately 75% and 82.42% of the IACS for electrical conductivity.