Electron beam welding–brazing (EBWB) was applied to join TA2 and 2024Al alloys with Al-Mg filler wire.
The effect of gap clearance on interfacial microstructures and mechanical properties of the butt Ti/Al joint
was discussed. Three types of intermetallic compound (IMC) layers, including discontinuous cellular shape,
continuous serrated shape, and discrete club shape, were presence at the TA2 interface. With the increase of
gap clearance, the thickness of the IMC layer increased gradually, and the morphology of IMC layer
changed from cellular shape to serrated shape and ultimately to club shape. The IMC layer was mainly
TiAl3 compound, while the weld zone (WZ) comprised the predominant a-Al and bits of Al-Cu eutectic. The
tensile strength of Ti/Al joint first increased and then decreased with the increased gap clearance. When the
gap clearance of the butt configuration was 0.4 mm, the Ti/Al joint 3# exhibited the highest strength
(316.4 MPa), about 73.7% of that of the 2024Al matrix, which is due to the formation of a continuous
serrated-shaped IMC layer with a thickness of 1.36-2.3 lm.