Microstructure characteristics of laser forming repaired Ti60 alloy

The microstructure characteristics of laser forming repaired (LFR) Ti60 (Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-0.3Nb) as-deposited and annealed samples are analyzed. The microstructure of as-deposited repaired zone (RZ) consists of epitaxial columnar prior β grains, in which fine woven α laths and β-phase between α laths exist. The heat-affected zone (HAZ) experiences a continuous microstructural transition from duplex microstructure of the base metal zone (BMZ) to the microstructure of RZ. The presence of silicide precipitates is observed in both RZ and BMZ in an annealed sample by transmission electron microscopy. They are identified as (Ti, Zr) 6 Si 3 distributed mainly at the α/β interface with the size of 100 300 nm. The fine αprecipitates are detected in BMZ by electron diffraction; there was no α detected in RZ.