Fig. 1 Schematic diagrams showing the fabrication of AZ31/1100 and AZ31/ZG21 composite plates by co-extrusion

Fig. 2 a Low magnification and b high magnification cross sectional SEM micrographs of AZ31/1100 composite plate; c EDS mapping of b showing the elements distribution of Al (green points), Mg (red points)

Fig. 3 Cross sectional SEM micrographs and EDS mappings of AZ31/1100 composite plate after annealing: a and b 400 °C for 3 h; c and d 400 °C for 10 h. EDS mapping showing the elements distribution of Al (green points) and Mg (red points)

Fig. 4 Low magnification and high magnification cross sectional SEM micrographs of AZ31/ZG21 composite plate: a and b as-extruded plate, c and d after annealing at 400 °C for 10 h

Fig. 5 XRD patterns near the interface of composite plates: AZ31/1100 a as-extruded, b after annealing at 400 °C for 3 h and c after annealing at 400 °C for 10 h; AZ31/ZG21 d before and e after annealing at 400 °C for 10 h

Fig. 6 Bright-field TEM image of interface zone of composite plates: a the extruded AZ31/1100 composite plate and b the AZ31/ZG21 composite plate after annealing at 400 °C for 10 h

Fig. 7 Inverse pole figure and pole figure of the AZ31 layer in AZ31/1100 composite plates: a as-extruded, b after annealing at 400 °C for 3 h and c after annealing at 400 °C for 10 h. ED, TD and ND refer to the extrusion direction, transverse direction and normal direction, respectively

Fig. 8 Inverse pole figure and pole figure of the 1100 layer in AZ31/1100 plates: a as-extruded, b and c after annealing at 400 °C for 3 h and 10 h, respectively

Fig. 9 Inverse pole figure and pole figure of the AZ31 and ZG21 layers in AZ31/ZG21 plates: AZ31 layer a before and c after annealing at 400 °C for 10 h; ZG21 layer b before and d after annealing at 400 °C for 10 h

Fig. 10 Engineering stress-strain curves under tension along the ED of the AZ31 layer, 1100 layer and AZ31/1100 plates: a as-extruded, b after annealing at 400 °C for 3 h and c after annealing at 400 °C for 10 h

Fig. 11 Engineering stress-strain curves under tension along the ED of the AZ31 layer, ZG21 layer and AZ31/ZG21 plates: a before and b after annealing at 400 °C for 10 h

Fig. 12 Peeling strength of the extruded and the annealed AZ31/1100 and AZ31/ZG21 composite plates

Fig. 13 Cross-sectional SEM micrographs of AZ31/1100 and AZ31/ZG21 plates after tension different strains along the ED: a the extruded AZ31/1100 plate, b and c the annealed AZ31/1100 plate (400 °C for 10 h), d the annealed AZ31/ZG21 plate (400 °C for 10 h)

Fig. 14 Fracture features of AZ31/1100-1 plate after the tensile test: the extruded a AZ31 layer and d 1100 layer, the annealing at 400 °C for 3 h b AZ31 layer and e 1100 layer, the annealing at 400 °C for 10 h c AZ31 layer and f 1100 layer

Fig. 15 Fracture features of AZ31/ZG21-1 plate after the tensile test: the extruded a AZ31 layer and c ZG21 layer, the annealing at 400 °C for 10 h b AZ31 layer and d ZG21 layer