Characterization and Mechanism of α₂-Ti₃Al and γ-TiAl Precipitation in Ti-6Al-4V Alloy Following Tungsten Arc Welding

Abstract:

Post-weld heat treatments were carried out in Ti-6Al-4V (Ti-6-4) weldments after a gas tungsten arc welding (GTAW) process. The α₂-Ti3Al compound formed in the fusion zone (FZ) following the annealing process, whereas the γ-TiAl, α₂-Ti₃Al compounds formed in the FZ and heat affected zone (HAZ) respectively following a solution plus aging treatment. These γ-TiAl and α₂-Ti₃Al that formed in the FZ and HAZ respectively are associated with a low ductility of the Ti-6-4 weldment to 2.8%. In contrast, the only presence of α₂-Ti₃Al in the FZ still maintains good ductility to 10.8%. Possible mechanisms for γ-TiAl and α₂-Ti₃Al compound formation in related regions of weldment are discussed.

• Periodical: Key Engineering Materials (Volume 520)
• Pages: 320-329
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.520.320
• Online since: August 2012
• Authors: L.M. Wang, H.C. Lin, C.J. Tsai
• Keywords: Heat Treatment, HRTEM, Microstructure, Phase Diagram, TiAl

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