Effect of harmonic vibration during gas metal arc welding of AA-5083 aluminum alloy on the formation and distribution of intermetallic compounds

Abstract

The distribution, size, and amount of intermetallic compounds (IMCs) due to the effect of applied harmonic vibration during gas metal arc welding (GMAW) of AA-5083-H321 aluminum alloy joints were characterized in this research. For this purpose, three groups of specimens were welded, whereas nine samples welded while vibration was applied, and the other without vibration. The experimental procedures conducted to investigate the microstructure of the weld samples, including optical microscopy (OM), scanning electron microscopy (SEM) equipped with a wavelength dispersive X-ray spectroscopy (WDS), X-ray diffraction (XRD), simultaneous thermal analysis (STA), and a statistic method based on Murakami's method of rating the inclusion. The results show that mean grain size of the non-vibrated welded sample was about 200 μm. While, it decreased significantly due to the application of vibration during welding, even to about 50 μm. It was also, observed that due to the conventional GMAW, IMCs such as Al6Mn and Al3Fe became fine, and was distributed as a semi-continuous network in the matrix. While, by the effect of vibration, the area fractions of IMCs were increased significantly. Moreover, with increasing the vibration force, IMCs were increased in both amount and size. On the other hand, the samples were welded with the vibratory force of 400 N, 2200 N, and 3150 N, the IMCs size was increased about 7 %, 13 %, and 26 % respectively, compared to that of the sample was welded without vibration.