Fig. 1. Microstructure of Ti47 matrix

Fig. 2. Schematic of laser reciprocating scanning

Fig. 3. Cross sectional morphologies in single track remelting for 1 time under different scanning speeds. (a) 900 mm·s-1; (b) 800 mm·s-1; (c) 700 mm·s-1; (d) 600 mm·s-1; (e) 500 mm·s-1; (f) 400 mm·s-1; (g) 300 mm·s-1; (h) 200 mm·s-1; (i) 100 mm·s-1

Fig. 4. SEM photos of areas indicated in Fig. 3 (g). (a) Middle part of molten pool; (b) bottom of molten pool; (c)(d) upper right side of molten pool

Fig. 5. SEM photos of microstructures of matrix

Fig. 6. XRD test results of matrix and remelting region after single track remelting for 1 time

Fig. 7. Metallographic photos of transition zone after single track remelting for 1 time at scanning speed of 700 mm·s-1. (a) Upper left side of molten pool; (b) bottom of molten pool

Fig. 8. Metallographic photos of transition zone after single track remelting for 1 time at scanning speed of 100 mm·s-1. (a) Upper left side of molten pool; (b) waist of molten pool; (c) bottom of molten pool

Fig. 9. Metallographic photos at different positions of matrix after single track remelting for 1 time at scanning speed of 500 mm·s-1

Fig. 10. Cross sectional morphologies after single track remelting under different scanning speeds and remelting times. (a) 2 times, 1000 mm·s-1; (b) 2 times, 900 mm·s-1; (c) 2 times, 700 mm·s-1; (d) 3 times, 1000 mm·s-1;(e) 3 times, 900 mm·s-1; (f) 3 times, 700 mm·s-1

Fig. 11. Cross sectional morphologies after single track remelting under different scanning speeds and remelting times. (a) 2 times, 500 mm·s-1; (b) 2 times, 300 mm·s-1; (c) 3 times, 500 mm·s-1; (d) 3 times, 300 mm·s-1

Fig. 12. Cross sectional morphologies after overlap remelting. (a) Scanning area of 2 mm×2 mm; (b) scanning area of 14 mm×14 mm