Fig. 1. Characterizations of the Ti-12Mo-xZr (x = 3, 6, 10) alloys at ST state. (a) XRD profiles; (b) Optical images; (c) SAED patterns along the [110]β zone axis. The peak position of (110)β of the three alloys is magnified in inset of (a). Two of the four ω-variants, labelled ω1 and ω4, are also discriminated on the basis of the reflections in (c).

Fig. 2. True strain-stress curves of the ST Ti-12Mo-xZr (x = 3, 6, 10) samples, and the corresponding strain-hardening rate curves as function of true strain also shown in inset.

Fig. 3. XRD profiles of the ST sample of Ti-12Mo-xZr (x = 3, 6, 10) alloys after deformation until fracture.

Fig. 4. EBSD analysis of the Ti-12Mo-3Zr deformed sample taken from the same region at strain ε = 0.02 (loading), 0.04 (loading), and 0.04 (unloading), respectively. (a) IPF maps; (b) orientation maps for SIM α″ phase; (c) pole figures of β matrix and SIM α″. (RD - rolling direction, TD - transverse direction).

Fig. 5. EBSD analysis of the Ti-12Mo-6Zr (Type A) deformed sample taken from the same region at strain ε = 0.02 (loading), ε = 0.04 (loading), and 0.04 (unloading), respectively. (a) IPF maps; (b) orientation maps for α″ phase; (c) pole figures of β matrix, {332}<113> twinning and SIM α″. (RD - rolling direction, TD - transverse direction).

Fig. 6. EBSD analysis of the Ti-12Mo-10Zr deformed sample taken from the same region at strain ε = 0.02 (loading), 0.04 (loading), and 0.04 (unloading), respectively. (a) IPF maps; (b) orientation maps for α″ phase; (c) pole figures of β matrix, {332}<113> twinning. (RD - rolling direction, TD - transverse direction).

Fig. 7. TEM micrographs of Ti-Mo-Zr samples after tensile deformation to ε = 0.05: (a) bright-field (BF) image of the Ti-12Mo-3Zr showing SIM α" bands; (b) dark-field (DF) image of one variant of the SIM α" in (a); (c) BF image of the Ti-12Mo-6Zr showing primary 332 T bands and the primary SIM α"; (d) DF image of the primary SIM α" in (c); (e) BF image of the Ti-12Mo-10Zr showing primary 332 T bands with secondary 332 T bands; (f) DF image of (e) with the corresponding SAED pattern along [[1], [2], [3], [4], [5], [6], [7], [8], [9], [10]]β zone axis.

Fig. 8. TEM micrographs of Ti-12Mo-6Zr at ε = 0.05: (a) BF image of an array of dislocations piled up to the 332 T interface; (b-d) BF images of the three g conditions around [111] β zone axis.

Fig. 9. Schematic formation sequence of 332 T and SIM α″ during loading and unloading process in (a) Ti-12Mo-3Zr; (b) Ti-12Mo-6Zr and (c) Ti-12Mo-10Zr alloys.