fig5

Figure 5. Microstructural evolution of α-phase under O-Fe microalloying: (A₁-A₃) SEM morphology of Ti-6Al-4V welded joint; (B₁-B₃) SEM morphology of Ti-6Al-4V-0.5O-2.3Fe welded joint; (C) Statistical results of the long and short diameters of the plate α phase; (D₁-D₃) Schematic diagrams of the growth process of columnar crystals with and without O-Fe element strengthening. Error bars represent the standard deviation (n ≥ 100 phase dimensions measured per weld zone).