Fig. 1 Photograph of rotating tool and schematics of FSW

Fig. 2 a Schematic illustration of surface and base bending tests for FSW Mg joint and b distribution of black speck markers on white matrix

Fig. 3 OM and EBSD maps of BMs: a AZ31 BM; b AM60 BM

Fig. 4 Macrostructure of the cross section of joint

Fig. 5 IPF maps in various regions of the joint

Fig. 6 (0001) pole figures in various regions of the joint

Fig. 7 a Stress-strain curves and b fracture morphologies of the BMs and the joint in bending

Fig. 8 Strain distribution of the two BMs: a AM60 BM; b AZ31 BM; c strain component in εX of AM60 BM; d strain component in εX of AZ31 BM

Fig. 9 Strain distribution maps of the joint: a surface test; b base test; c strain component in εX of surface test; d strain component in εX of base test

Fig. 10 SF distributions for extension twinning and basal slip of each region in joint: a flexural stress diagram; b basal slip; c extension twinning for tension; d extension twinning for compression

Fig. 11 Mean SF distributions for extension twinning and basal slip of each region in joint

Fig. 12 EBSD maps of base test sample after bending (corresponding to R1, R2 and R3 in Fig. 13a): a NZ side (AM60 side); b NZ center; c NZ side (AZ31 side)

Fig. 13 Texture evolutions in the various regions of the bending joint after 95% under the maximum bending strength: a base test; b surface test

Fig. 14 EBSD maps of base test sample after 95% under the maximum bending strength

Fig. 15 OM maps of NZ center in the compression zone of the base test sample

Fig. 16 a Schematic illustration of shear layer formation tempted by the rotation of friction stir welding pin; b SF distribution for basal slip in R5 after bending; c SF distribution for basal slip in R1 and R2 after bending; d schematic diagram of extension twinning variants

Fig. 17 EBSD maps of surface test sample after 95% under the maximum bending strength

Fig. 18 EBSD maps of BMs: a AZ31 BM; b AM60 BM

Fig. 19 KAM maps of joint: a AZ31 side; b AM60 side