In the welding process of thick-walled titanium alloys, the selection of the wire type is one of the critical factors affecting the welding quality. In this paper, flux-cored and cable wires were used as filler materials in the welding of thick-walled titanium alloys. The macrostructure, microstructure, texture, and grain size of both welded joints were compared by employing an optical microscope (OM), scanning electron microscope (SEM), and transmission electron microscope (TEM), and the tensile and impact properties were also evaluated. The comparison result showed that the fusion zone microstructure of both welded joints was dominated by a basketweave structure composed of interwoven acicular α′ martensite, whereas the microstructure of flux-cored wire welded joints was finer, and the degree of anisotropy was low. The strength of both welded joints was higher than that of the base metal, ensuring that fracture occurred in the base metal area during tension. The Charpy impact energy of the flux-cored wire welded joint was 16.7% higher than that of the cable wire welded joint, indicating that the welded joint obtained with the flux-cored wire performed better in the welding process of thick-walled titanium alloys.

A self-developed Ti-Al-V-Mo system titanium alloy flux-cored wire was used to join the Ti64 titanium alloy plate via laser welding with filler wire. The microstructure and properties of the obtained welded joint were investigated. The results showed the WM (welded metal) of the welded joint consisted mainly of acicular α’ martensite, and the HAZ (heat affected zone) was comprised of a primary α_p phase, Widmanstatten, and a few α’ martensite and a residual β phase. The strength and elongation of the welded joint after breaking are equivalent to that of the BM (base metal). The tensile fracture, presenting as a microvoid coalescence ductile fracture, was encompassed by massive shear lips with deep and uniform dimples. The overall microhardness of the welded joint was sequenced as WM > HAZ > BM. In the WM, large-angle grain boundaries with intragranular misorientation greater than 15° accounted for about 84%. By XRD, it was discovered the welded joint was mainly composed of the α’ martensite, with a modest amount of extremely weak multi-angle α phase diffraction peak. The test results showed the designed welding method of titanium flux-cored wire and laser wire filling is suitable for high-quality welding of titanium alloy plate.