Comparative Analysis of Weld Microstructure in Ti-6Al-4V Samples Produced by Rolling and Wire-Feed Electron Beam Additive Manufacturing

The microstructure and phase composition of electron beam welded Ti-6Al-4V titanium alloy were studied by optical and scanning electron microscopy, backscattered electron diffraction, and X-ray diffraction analysis. Deep-penetration electron beam welds were made in a single pass on rectangular Ti-6Al-4V samples obtained by rolling and wire-feed electron beam additive manufacturing. It was found that the weld width in the 3D printed Ti-6Al-4V samples is greater than in the rolled material. The influence of the vapor capillary on the size, shape and structure of primary β grains formed in the fusion zone was shown. The variation of the penetration coefficient, volume fraction of the residual β phase, and residual stresses along the weld length was studied for Ti-6Al-4V samples obtained by both rolling and 3D printing.