Abstract
The paper concerns the analysis of the influence of the focusing current on the microstructure of aluminum alloy welded joints produced by electron beam welding. 2219 high-strength aluminum copper alloy was used as the base material. 2219 aluminum alloy is extensively used in the aerospace industry due to its excellent mechanical properties, high strength-to-weight ratio, and good corrosion resistance. Fuselage skins, wing panels, and rocket fuel tanks are some of the applications of the mentioned alloy. Bead-on-plate welded joints were produced within the study. Focusing currents of 629, 634, 639, 644, and 649 mA were utilized. Focusing current 639 mA ensures a sharp focus. The higher focusing current resulted in the production of a smoother weld bead. The narrowest weld was recorded when 629 mA focusing current was used. In the case of focusing currents 639, 644, and 649 mA, it can be stated that the higher the focusing current, the narrower the weld root. Except for a slight deviation in the case of the 629 mA focusing current application, the higher the focusing current, the larger the cross-sectional area of weld metal. Furthermore, the higher the focusing current, i.e., set up the focus position above the surface of materials to be welded, the larger the dendrite size. The finest dendrites were observed in the case of 629 mA focusing current (under focusing of the electron beam). Contrarily, the coarsest dendrites were documented when the highest focusing current, i.e., 649 mA, was used (over-focusing of the electron beam).