Characterization of yttrium-rich precipitates in a titanium alloy weld

The yttrium-rich (Y-rich) precipitates that form in the fusion zone (FZ) of a Ti-5Al-1Sn-1Zr-1V-0.8Mo (wt.%) alloy, or Ti-5111, gas-tungsten arc welds (GTAW) were characterized. The filler metal was modified by a small concentration of Y in order to refine the microstructure and thus improve the FZ ductility. A high number density of nanoscale Y-rich precipitates were characterized in the weld FZ by atom probe tomography (APT) and scanning transmission electron microscopy (STEM).