Effect of process parameters on porosities in electron beam welded AA-6061 to AA-2024 dissimilar joints

The electron beam welding process was used to produce dissimilar butt-joints of AA-6061 to AA-2024 sheets using various welding conditions such as different welding speed, double-side pass, and various oscillating beam patterns (circular, straight-ramp, triangular, and infinity). The joints were subjected to x-ray computed tomographic analysis to visualize and quantify insidious welding defects like porosities and microcracks. Such inspection revealed the presence of porosities in all joints, regardless of their welding conditions. Besides, variation in EBW welding conditions was found to alter the porosity content, size, and distribution. When the welding speed was increased, the porosity content and pore volume fractions were reduced by 30%, while a significant reduction (80-90%) was obtained for the oscillating or double-side pass conditions. In oscillating beam conditions, the triangular pattern was found to be more effective in reducing weld porosities, whereas the infinity pattern was unsuitable for joining aluminum alloys.