Fig. 1. Structures of as-deposited TC4. (a) Z-direction macrostructure; (b) XY-direction macrostructure;(c) Z-direction microstructure; (d) XY-direction microstructure

Fig. 2. Microstructures obtained after solution treatment with different temperatures. (a)(b) 910 ℃/1 h/WQ+550 ℃/4 h/AC; (c)(d) 950 ℃/1 h/WQ+550 ℃/4 h/AC; (e)(f) 990 ℃/1 h/WQ+550 ℃/4 h/AC

Fig. 3. Microstructures of TC4 alloy after solution treatment with different time.(a)(b) 950 ℃/0.5 h/WQ+550 ℃/4 h/AC; (c)(d) 950 ℃/1.5 h/WQ+550 ℃/4 h/AC

Fig. 4. Microstructures after treatments at different aging temperatures. (a)(b) 950 ℃/1 h/WQ+500 ℃/4 h/AC; (c) enlarged view of white box in Fig. 4(b); (d)(e) 950 ℃/1 h/WQ+550 ℃/4 h/AC; (f) enlarged view of white box in Fig. 4(e); (g)(h) 950 ℃/1 h/WQ+600 ℃/4 h/AC; (i) enlarged view of white box in Fig. 4(h)

Fig. 5. Microstructures of TC4 alloy after aging treatment with different time. (a)(b) 950 ℃/1 h/WQ+550 ℃/2 h/AC;(c) enlarged view of white box in Fig. 4(b); (d)(e) 950 ℃/1 h/WQ+550 ℃/6 h/AC; (f) enlarged view of white box in Fig. 5(e)

Fig. 6. XRD patterns of as-deposited and solution aging TC4 alloy specimens

Fig. 7. Shape and sizes of tensile specimens (M represents nominal diameter of thread, R represents radius, and Φ represents diameter)

Fig. 8. Fracture morphologies of tensile specimens at as-deposited state and after solution-aging treatment.(a) As-deposited state specimen; (b) solution-aging specimen