Fig. 1. Microstructure of fine-grained TZA822 alloy: (a) OM, (b) SEM, (c) the EDS results of the second phases in (b) and (d) grain size distribution.

Fig. 2. True stress-true strain curves of fine-grained TZA822 alloy at different temperatures with strain rate: (a) $\dot{ε}$ =0.01 s-1; (b) $\dot{ε}$ =0. 1 s-1; (c) $\dot{ε}$ =1 s-1; (d) $\dot{ε}$ =10 s-1.

Fig. 3. Variation of peak stress for fine-grained TZA822 alloy upon different strain rate (a) and deformation temperature (b).

Fig. 4. Relationship between: (a)ln$\dot{ε}$-lnσ,(b)ln$\dot{ε}$-lnσ-σ, (c) ln$\dot{ε}$-ln[sinh(ασ)] and (d)ln[sinh(ασ)] -1/T.

Fig. 5. (a) Linear relationship betweenlnZ-ln[sinh(ασ)], (b) the comparison of the calculated and measured peak stress.

Fig. 6. Processing map of the fine-grained TZA822 alloy at the strain of 0.1 (a), 0.3 (b), 0.5 (c) and 0.7 (d).

Fig. 7. Variation of the work hardening rate (θ) with different temperatures (a) and strain rate (b).

Fig. 8. The Schematic diagram defining and exhibiting how to calculate σs and θ0.

Fig. 9. Microstructures of fine-grained TZA822 alloy deformed at (a) 300 °C/0.01 s-1, (b) 350 °C/0.01 s-1 and (c) 350 °C/10 s-1.

Fig. 10. The EBSD analysis of TZA822 alloy deformed at 350 °C/0.01 s-1 and 350 °C/10 s-1: (a) and (b) grain boundary maps; (c) and (d) misorientation profiles along the line marked in (a) and (b); (d) and (e) (0001) pole figures.

Fig. 11. The TEM micrographs of TZA822 alloy deformed at 350 °C/0.01 s-1 exhibiting: (a) dislocation network, (b) dislocations arrays, and (c) subgrains and (d) DRX grain; (e) DDRX and (f) CDRX deformed at 350 °C/10 s-1.

Fig. 12. Schematic summaries the two different DRX mechanisms.

Fig. 13. Microstructures of TZA822 alloy deformed at: (a) 200 °C/10 s-1, (b) 250 °C/10 s-1.