Abstract:Electron beam welding of Ti-15-3 titanium alloy to 304 stainless steel with a copper sheet as interlayer was carried out. Microstructures of the joint were studied by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). In addition, the mechanical properties of the joint were evaluated by tensile test and the microhardness was measured. These two alloys were successfully welded by adding copper transition layer into the weld. Solid solution with a certain thickness was located at the interfaces between weld and base metal in both sides. Regions inside the weld and near the stainless steel were characterized by solid solution of copper with TiFe₂ intermetallics dispersedly distributed in it. While weld near titanium alloy contained Ti-Cu and Ti-Fe-Cu intermetallics layer, in which the hardness of weld came to the highest value. Brittle fracture occurred in the intermetallics layer when the joint was stretched.

Key words: Ti-15-3 titanium alloy; 304 stainless steel; electron beam welding; intermetallics layer; mechanical properties