The effect of harmonic vibration with a frequency below the resonant range on the mechanical properties of AA-5083-H321 aluminum alloy GMAW welded parts

The effects of vibration on the tensile properties and hardness of gas metal arc welded (GMAW) AA-5083-H321 aluminum alloy samples have been investigated. Vibration forces ranged from 400 N to 1000 N were applied with an AC vibrator motor at a frequency of 50 Hz, while the samples were welded. The samples were studied by optical microscopy, tensile and microhardness tests. Finally, the fracture surfaces were analyzed using scanning electron microscope (SEM). Compared to that of the sample was welded with conventional GMAW, in the samples were welded while vibration applied, with increasing vibration force from 400 N to 750 N and ultimately to 1000 N, tensile strength increased 3% and also, elongation increased 6%, 9%, and 16.5% correspondingly. However, no significant change was observed in the hardness of the welds. Moreover, the mean grains size of vibrated and non-vibrated welding samples were about 115 mu m and 200 mu m, respectively.