Abstract
Vibratory weld conditioning (VWC) was performed on the AA-5083 aluminum alloy specimens while they were welded with gas metal arc welding (GMAW). The variables in this study were vibration forces range from 400–3150 N and vibration frequency of 50–90 Hz. Microstructure, residual stress, and fatigue crack growth behavior of the welded samples were examined. Fracture analysis was also undertaken after the fatigue crack growth test using a scanning electron microscope (SEM). The results show that compared to the no-vibration welded sample, with increasing vibration forces, the columnar structure was replaced by equiaxed grains, and the area fraction of equiaxed grains increased to 75 %. In contrast to the sample welded without vibration, residual stress decreased while vibration was applied during welding. On the other hand, the application of mechanical vibration during welding, at each given frequency of 50, 75, and 90 Hz caused residual stress decrement of about 36, 38, and 44 %. At low ΔK values, the crack growth rate is low in all welded specimens and is approximately similar to the crack growth rate of the no-vibration welded specimen. Tensile residual stress is an effective reason that caused the crack growth rate of the material to increase.

Key words
vibratory weld conditioning (VWC), equiaxed grain, residual stress, 5083 aluminum alloy, fatigue crack growth

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