Fig. 1. SF of {10-12} twinning system as a function of the angle between loading axis and c-axis. (a) Tension [11] and (b) compression [30]. Information for six twin variants is given in the insert.

Fig. 2. Optical microstructures and (0002) pole figures with (a) compression strain along rolling direction (RD) (i.e. compression perpendicular to c-axis of texture) and (b) tension strain along the normal direction (ND) (i.e. tension along c-axis of texture). The twinned regions are indicated as a bright color in (a) and a dark color in (b). TD means transverse direction [11].

Fig. 3. (0001) pole figure of (a) as-rolled AZ31 plate, (b) after 3% compression along the TD, (c) after 3% compression along the TD and then 3% compression along the RD. The blue arrows and red arrows indicate the twin-orientations with c-axis//RD and c-axis//TD, respectively [32].

Fig. 4. (0002) pole figures and misorientation angle maps of the various pre-stretched samples: (a) 2.3% pre-stretched; (b) 5.4% pre-stretched and (c) 8% pre-stretched along the TD of the hot-extruded sheet (Mg-3Al-Zn alloy with 3 wt.% Li addition) [41].

Fig. 5. In-situ EBSD measurement results (inverse pole figure map, and corresponding (0001) and (10-10) pole figures): the rolled AZ31 plate (a) compressed to a strain of 2% along the RD and subsequently tensioned to strains of (b) 3% and (c) 5% along the ND (Vf: twin volume fraction) [14].

Fig. 6. Twinned volume fraction with strain along the RD and ND of a rolled AZ31 plate. The value at each condition is an average measured over five different micrographs [11].

Fig. 7. Stresses required for activating basal and prismatic slips, {10-12} twinning under tension (a) and compression (b) in an AZ31 alloy [50].

Fig. 8. Calculated slip/twinning activities under uniaxial compression along various angle from ND to TD of a rolled AZ31 plate. (a) 0° (ND), (b) 30°, (c) 60° and (d) 90° (TD). The Y-axis is simulated relative activity of various deformation modes [52].

Fig. 9. (a) A calculation of the ratio of the increase in CRSS for {10-12} twin growth compared to the increase in CRSS for prismatic slip for plate, rod and spherical particles. Particle volume fraction = 5%, aspect ratio of plates = 0.1, aspect ratio of rods = 10. [12] (b) Hall-Petch plots showing the influence of grain size on σ0.002 and σ0.2 for 150 °C [65].

Fig. 10. Pole figures (measured by XRD) before and after annealing at 450 °C for 4 h for samples 0%, 2% 4% and 5% pre-compressed along the ED of an extruded AZ31 rod. RD-radial direction, and TD-tangential direction [83].

Fig. 11. EBSD maps and {0001} pole figure of twinned AZ31 sheets by a continuous bending channel in a rolling device: (a) before annealing and (b) after annealing at 350 °C [85].

Fig. 12. The schematic diagram of deformation of (a) vertical rolling and (b) vertical compression [86,87].

Fig. 13. Overview about the thin sheet compression die from (a) Ref. [24], (b) Ref. [26], (c) Ref [25]. and Ref. [91].

Fig. 14. (a) Physical diagram, (b) schematic diagram of simple shear device, (c) deformation feature of in-plane shear, (d) {0001} pole figure of rolled AZ31 sheet and (e) {0001} pole figure of rolled AZ31 sheet underwent a strain of 5% by in-plane shear deformation. The red arrows represent twin-orientation [92].

Fig. 15. EBSD maps and (0002) pole figures of various positions in a bended AZ31 sheet: (a) outer surface zone; (b) middle zone; (c) inner surface zone; and (d) measurement positions for EBSD analysis in the RD-ND plane. Position (b) is near the convex side, (c) at the center and (d) near the concave side [95].

Fig. 16. (a) Repeated unidirectional bending [98], (b) continuous bending process [99], (c) repeated roll bending process [100] and (d) continuous bending channel rolling [85].