Fig. 1 Schematic of the ARR process a initial stage; b stable rolling stage

Fig. 2 Effective stress and strain distributions of AZ91 sheets with a 30% reduction obtained from FE simulation: a effective stress distribution of ARR; b effective stress distribution of SR; c effective strain distribution of ARR; d effective strain distribution of SR

Fig. 3 Schematic illustration of the sample for rolling taken from a cast ingot

Fig. 4 Optical micrographs of the as-homogenized AZ91

Fig. 5 Optical microstructure of a as SRed AZ91; b SRed AZ91 in annealed condition

Fig. 6 Optical microstructure of a, b as ARRed AZ91 sheet; c ARRed AZ91 in annealed condition

Fig. 7 Details of black area in ARRed AZ91 rolling sheets: a SEM image; b EDS result for phase A; c EDS result for phase B

Fig. 8 Inverse pole figure (IPF) maps of the rolled AZ91 Mg alloy obtained by EBSD: a SRed AZ91; b ARRed AZ91 Figure 9 shows Schmid factor (SF) distribution maps for basal <a> slip system of AZ91 sheets processed by ARR and SR process, obtained by EBSD analysis. It can be observed that for SR sheet with a stronger basal texture, the average of Schmid factor (ASF) in the basal plane is 0.29, while for ARR sheet with a weakened basal texture that is 0.34, which is slightly higher than that of SR sheet. Thus, it is more easy to activate the basal slip during deformation, which results in an improvement in the plasticity of AZ91 alloys.

Fig. 9 Schmid factor of AZ91 sheets processed by a ARR; b SR with a 30% reduction

Fig. 10 Stress-strain relations of AZ91 processed by SR and ARR