Fig. 1. Phase diagram of Ti-Al binary alloy

Fig. 2. Microstructures of deposited layer. (a) Bottom area of deposited layer; (b) top area of deposited layer

Fig. 3. Microstructures of TC4 titanium alloy under different normalizing heat treatments. (a) As-deposited (before normalizing); (b) 810 ℃/2 h/AC; (c) 870 ℃/2 h/AC; (d) 930 ℃/2 h/AC; (e) 990 ℃/2 h/AC

Fig. 4. Effect of normalizing temperature on primary α-Ti phase. (a) Effect on length and width; (b) effect on aspect ratio and volume fraction of α-Ti phase

Fig. 5. SEM images of normalizing at different temperatures in α+β phase zone. (a) 930 ℃/2 h/AC;(b) enlarged view of box in Fig. 5(a); (c) 990 ℃/2 h/AC; (d) enlarged view of box in Fig. 5(c)

Fig. 6. Schematic of microstructure transformation under 990 ℃/2 h/AC normalizing heat treatment

Fig. 7. XRD patterns of TC4 titanium alloy under different normalizing heat treatments

Fig. 8. Tensile fracture morphologies at room temperature of TC4 titanium alloy under different normalizing heat treatments.(a) As-deposited (before normalizing); (b) 810 ℃/2 h/AC; (c) 870 ℃/2 h/AC; (d) 930 ℃/2 h/AC; (e) 990 ℃/2 h/AC