Abstract:
The self-piercing riveting joints of 5HF aluminum alloy at different riveting rates were analyzed, and the influence mechanism of the stacking sequence of aluminum alloy sheets and adhesives on the process and mechanical properties of the riveted joints were studied. The results show that the combination of upper thin and lower thick exhibited better process robustness, with a wider riveting rate window of 115 mm/s compared to 95 mm/s for the combination of upper thick and lower thin. The average interlocking value was 0.72 mm, which was higher than the 0.28 mm for the combination of upper thick and lower thin. The upper thin and lower thick joint experienced tearing of the top plate base material due to sufficient interlocking, resulting in strong joint failure, while the upper thick and lower thin joint experienced rivet extraction or connection point damage due to shallow interlocking. After introducing adhesive in the combination of thin top and thick bottom, the riveting rate window was reduced to 100 mm/s. However, through the collaborative load-bearing of the adhesive layer and mechanical interlocking, the shear strength of the joint could be increased to 1.9—2.16 times that of non adhesive riveting, and the fracture mode could be uniformly and stably transformed into top plate tearing, indicating that the bottleneck of joint strength shifted from the connection interface to the base material body.