Fig. 1. Schematic processing routes for lamellar and equiaxed microstructures. The two microstructures were then subjected to cross rolling at 700 °C.

Fig. 2. Schematic diagram of rolling route in cross rolling (CR).

Fig. 3. EBSD maps showing of the (a-c) lamellar-CR and (d-f) equiaxed-CR samples with reductions of 20 %, 50 % and 80 %, respectively.

Fig. 4. Texture evolution of the α and β phases in the lamellar-CR samples with the increasing rolling reduction.

Fig. 5. Texture evolution of the α and β phase in the equiaxed-CR samples with the increasing rolling reduction.

Fig. 6. Tensile strength and elongation of the lamellar-CR and equiaxed-CR samples with reductions of 20 %, 50 % and 80 %, respectively.

Fig. 7. Fracture morphologies of the (a, c) lamellar-CR and (b, d) equiaxed-CR samples with a reduction of 80 %.

Fig. 8. (a), (c) BF images taken from the lamellar-CR samples processed at 20 % and 80 % rolling reduction, respectively. (b) high-resolution TEM micrograph (HRTEM) and the corresponding FFT image of the area selected in HRTEM image showing activation of the {1$\bar{1}$01} twin in the lamellar α phase in (a). (d) High-resolution TEM micrograph and the corresponding FFT image of the area selected in HRTEM image showing diffuse streaks along the $\langle 0 \bar{1}11\rangle ^{*}_{α}$ directions in the refined α phase in (c).

Fig. 9. (a) TEM BF image of the β-twinned region in the equiaxed-CR sample processed at 80 % rolling reduction. (b) The corresponding SAED pattern of the circled region in (a) along the [110]β zone axis showing the presence of two types of twins, namely {332}〈113〉 and {112}〈111〉 -type twins, in the twinned region. (c) Dark-field image obtained from {112}〈111〉 spot circled in yellow (DF1) and {332}〈113〉 spot circled in green (DF2) in (b).

Fig. 10. HAADF mapping images of the equiaxed-CR samples processed at 20 % rolling reduction, and the corresponding SAED pattern verified {1$\bar{1}$01} twin activated.

Fig. 11. HAADF mapping images of the equiaxed-CR samples processed at 50 % rolling reduction, and the corresponding SAED pattern verified {332}〈113〉 -type twin activated.

Fig. 12. HAADF mapping images of the equiaxed-CR samples processed at 80 % rolling reduction.

Fig. 13. Kernel average misorientation (KAM) map in the β matrix of the equiaxed-CR sample processed at 80 % rolling reduction.