Characterization of Dissimilar Linear Friction Welds of α-β Titanium Alloys

Characterization of dissimilar linear friction weld (LFW) of Ti-alloys has been carried out. The microstructure of a Ti-64 with Ti-6246 weld was analyzed using scanning and transmission electron microscopy. The microtexture of the weld was examined using electron back-scattered diffraction (EBSD) and the microhardness was measured. The dissimilar LFW weld shows an interface at the central weld zone (CWZ) with strong contrast. The element distribution measured using energy-dispersive X-ray spectrometer suggests that only limited atomic diffusion occurred during welding. In the weld region, the hardness of Ti-64 shows an increase while that of Ti-6246 shows a decrease, compared with the respective parent materials in as-welded condition. After post-weld heat treatment, a hardness increase was observed in Ti-6246, while Ti-64 shows no significant hardness increase. Although the EBSD pattern quality is poor in the CWZ at the as-welded condition, the pattern quality of the post-weld heat-treated sample shows that both the Ti-64 and Ti-6246 have similar texture.