Influence of Electron Beam Welding Parameters on the Properties of Dissimilar Copper–Stainless Steel Overlapped Joints

The paper deals with the analysis of the influence of welding parameters on the properties of dissimilar copper–stainless steel welded joints produced with electron beam welding. Electrolytic tough pitch (ETP) copper and AISI304 stainless steel were used as base materials. The thickness of base metals is 1.0 mm. Overlapped welded joints were manufactured. Different welding parameters were tested. Full factorial design of experiment (DoE) based on 3 factors and 2 levels was used within the study. Beam currents used for electron beam welding were 40 and 70 mA and welding speeds 30 and 40 mm/s. Welded joints were produced with and without beam oscillation. DoE results showed that the beam current had the highest influence on weld width at the surface of dissimilar metals. It was found that the application of higher beam current and higher welding speed resulted in the formation of large spiking at the weld root. Spiking was observed when beam current of 70 mA and welding speed of 40 mm/s were used independent on beam oscillation. Lower welding speed resulted in elimination of spiking. Large spiking could be associated with the capillary effect. Beam oscillation possessed the highest influence on the copper intermixing in the weld metal. Application of beam oscillation resulted in widening of weld metal at the surface, at the interface line between sheets and weld depth, as well. Furthermore, the beam oscillation shows the highest effect on the tensile strength of welded joints.