Properties of dissimilar aluminum joints for Al-Si/Al-Mg, Al-Cu, Al-Mg-Si, Al-Zn-Mg-Cu alloys by electron beam welding

Joints of aluminum-based dissimilar alloys can enhance design flexibility for various structures. Aluminum welded structure are often required welded joints for dissimilar alloys. In the present study, electron beam welds are produced for different kind aluminum alloys of 10 mm in thickness. Main alloys is extruded Al-Si plate. Combination wrought alloys are Al-Mg, Al-Cu, Al-Mg-Si and Al-Zn-Mg-Cu alloy plates. The electron beam machine is 6 kW for high voltage type. Joint configuration is I type and without filler metal. Hardness of Al-Si/Al-Mg and Al-Si/Al-Mg-Si weld metals are same levels as both alloys. Tensile strength becomes about 200 MPa. Tensile elongation for Al-Si/Al-Cu joint is the lowest level, and they are 80% of the base metal. Impact value shows a tendency to decrease. Micro-segregation of Mg, Si and Cu in weld metals are recognized for Al-Si/Al-Mg-Si joint.