Effects of process parameters on dynamic and static load capacity of EN AW-2024-T3 aluminum alloy joints prepared by friction stir welding

Abstract This study investigates the impact of friction-stir welding (FSW) process parameters on the mechanical performance and fracture behavior of EN AW-2024-T3 aluminum alloy joints. A series of static and dynamic mechanical tests were conducted on six welded samples, revealing that the joint strength and fracture characteristics are highly sensitive to FSW parameters, particularly tool rotational rate, pin length, and traverse speed. Sample III, which exhibited the optimal combination of parameters, achieved the highest static load capacity, reaching 98.5% of the raw material's strength. Dynamic testing further confirmed Sample III's superior performance, with the highest recorded load capacity and significant energy absorption, as evidenced by ductile fracture features and high surface roughness. In contrast, Sample V, characterized by an excessive pin length, showed the lowest static and dynamic strength, along with a brittle fracture mode. The surface topography and SEM analysis of fracture surfaces indicated that optimized FSW conditions promote a ductile fracture mode, enhancing joint toughness under dynamic loading. These findings underscore the critical role of process parameter optimization in improving the mechanical properties and fracture resistance of FSW aluminum joints, making them more suitable for applications subjected to static and dynamic loading.