Fig. 1. The microstructures of the AXM050703 slab after homogenization at 500 °C for 24 h: (a, b) optical micrographs, (c) TEM image, (d) [10-10] selected area electron diffraction (SAED) pattern of Mg2Ca phase, (e) EBSD image, (f) texture obtained from the RD-ND planes.

Fig. 2. Typical optical micrographs of the AXM050703 alloy samples after hot rolling to thickness reductions of (a, d, g, j) 10%, (b, e, h, k) 20% and (c, f, i, l) 40% at the slab temperature of 400 °C. (a-f) were observed on the RD-ND plane and (g-l) were observed on the RD-TD plane.

Fig. 3. EBSD results on the RD-ND plane of the AXM050703 alloy samples after hot rolling to thickness reductions of (a, b) 10%, (c, d) 20% and (e, f, g, h) 40% at 400 °C (The correlated OM microstructures are shown in Fig. 2(a-f)).

Fig. 4. TEM images on the RD-ND plane of the AXM050703 alloy samples after hot rolling to thickness reduction of 40% at the slab temperature of 400 °C. (a, b) shows the double twin DRX, (c, d) shows the kinks.

Fig. 5. Textures of the AXM050703 alloy samples after hot rolling to thickness reductions of (a, b) 10%, (c) 20% and (d, e, f) 40% at the slab temperatures of (a-e) 400 °C and (f) 350 °C. (a-d) were obtained from the RD-ND planes, (e, f) were obtained from the RD-TD plane.

Fig. 6. EBSD results on the RD-ND plane of the AXM050703 alloy samples after hot rolling to thickness reduction of 20% at the slab temperatures of (a, c) 350 °C and (b, d) 400 °C, showing the influence of slab temperatures on the rolled microstructures.

Fig. 7. Microstructures of the AXM050703 alloy samples after hot rolling to thickness reduction of 40% at the slab temperature of 350 °C: (a, b) EBSD image shows the double twins; (c) EBSD image shows the kinks; (d) TEM image shows the kinks and twins.

Fig. 8. (a) Change of sample temperature during hot rolling of Type 2 and Type 3 samples, (b) typical optical micrograph, (c) (0001) pole figure and (d) distribution of misorientation angle of Type 2 samples after rough rolling.

Fig. 9. The (0001) and (11-20) pole figures on the RD-TD planes of the completely rolled (a) Type 2 and (b) Type 3 samples. And the (0001) 〈11-20〉 basal slip schmid factors for (c, d, e) Type 2 and (f, g, h) Type 3 samples, (c, f) 0° samples, (d, g) 45° samples and (e, h) 90° samples.

Fig. 10. (a, b) EBSD results and (c, d) SEM images on the RD-TD planes of (a, c) Type 2 and (b, d) Type 3 samples, (e) DRXed grain size distribution histogram obtained from the RD-TD planes of Type 2 and Type 3 samples.

Fig. 11. TEM microstructures obtained from the RD-TD planes of (a) Type 2 and (b) Type 3 samples.

Fig. 12. The stress-strain curves obtained from tensile tests on the (a) Type 2 and (b) Type 3 samples. For comparison, the σTPS of commercial AZ31B sheet [4] and T6-treated medium-strength 6061 aluminum alloy [53] are also included.