An experimental approach for achieving high strength dissimilar aluminium-magnesium joints: Application of tool pin profiles on different joint configurations

The goal of this study is to overcome difficulties in producing high-strength dissimilar aluminum-magnesium (Al-Mg) joints by friction stir welding (FSW). It analyses the effect of joint configurations and tool pin profiles on weld characteristics, with a focus on microstructural and mechanical aspects to establish optimal welding settings. The effect of process variables such as tool rotation speed (TRS) and traverse speed (TTS) on material flow and heat input is investigated. The findings reveal that the newly created joint configuration and tool pin shapes successfully link various Al-Mg FSW welds. The amount of heat used and the peak temperature reached during welding have a major impact on microstructure refinement and mechanical characteristics. The study investigates the relationship between heat input and the development of intermetallic compounds, emphasizing the need to optimize welding settings for strong interfacial bonding and joint integrity. The surface morphology and macrostructure of the welds are examined to determine their quality and faults. The tool pin profile influences material consolidation, flash defects, and surface peeling. Threaded conical tools outperform conical tools in terms of surface polish and flash expulsion. Overall, this study emphasizes the importance of changing joint configurations and selecting proper tool pin profiles when utilizing FSW to generate high-strength dissimilar Al-Mg couplings.