Effect of Beam Oscillations on Formation of Defects in Electron Beam Welding of Copper Plate

Abstract

Abstract In the present study, electron beam welding bead-on-plate of electrolytic pitched copper (ETP-Cu) plate was carried out to study the behavior of different defects formed in the weld by varying the beam oscillation amplitudes. The defects like spattering, spiking and porosity were considered in this study. Spattering and spiking phenomena were determined with visual inspection and image analysis software, respectively. Porosity measurement was conducted with X-ray tomography. Spattering was found to decrease with the oscillation amplitude up to the optimized value and then, it showed an increasing effect with it. Spatters in the weld also contributed to the pore formation in the weld by the inside pores available in it. Spiking was found to be more dynamic, and not directly related to the oscillation amplitude. But, in general, it was increasing with the increase of amplitude. Spiking was found to have a linear relationship with mean diameter of pores, which implied that a weld with the sharper spikes was more prone to large size root pores in the weld. Mean diameter and volume fraction of the pores were tending to increase with oscillation amplitude; however, there were discontinuities in the trend at the optimized amplitude value. An optimized value of oscillation amplitude was found to be useful for suppressing these defects in the weld. However, a random oscillation amplitude could be more detrimental to the quality of the weld joint.