Influence of beam oscillation patterns on the structure and mechanical properties of Ti–6Al–4V electron beam weldments

The present study deals with the effect of beam oscillation patterns on the structure and mechanical properties of Ti–6Al–4V electron beam weldments. Electron beam welding of Ti–6Al–4V sheets was done with beam oscillation in various patterns (sinusoidal, square, triangular and elliptical). Welding without beam oscillation was also done for comparison. Room temperature hardness and tensile properties at different temperatures (room temperature, 150, 300 and 450°C) of the weldments in both as welded and post-welding heat treated conditions were observed and their correlations with the microstructure studied. The beam oscillated weldments showed higher ductility and lower strength (hardness) compared with those without being beam oscillated. This was attributed to wider diffusional α plates in the beam oscillated welds owing to slower cooling rates. Elliptical oscillation pattern produced weldments possessing the highest ductility and lowest strength values compared with other oscillation patterns. The oscillating patterns of sinusoidal, square or triangular forms resulted in weldments with almost the same structure and properties.