Fig. 1 a Schematic diagram of the MDIF process, b extension in the forging passes up to 50 at 450 °C, c machined out samples position from the center of MDIFed sample

Fig. 2 a Cast microstructure of GW94 Mg alloy as shown in OM image, b solid solution-treated microstructure, c SEM image of solid solution-treated sample

Fig. 3 The optical microstructures of GW94 Mg alloy MDIF 30 passes at different temperatures: a 350 °C, b 400 °C, c 450 °C, d 500 °C

Fig. 4 a Inverse pole figure map, b corresponding grain boundary map of the GW94 alloy after MDIF 30 passes at 400 °C, whereas c-f the enlarged IPF maps selected in a, b displaying the formation of extension twins and low-angle grain boundaries

Fig. 5 a Inverse pole figure map, b corresponding grain boundary map of the GW94 alloy after MDIF 30 passes, where c-e the enlarged IPF maps selected in a, showing few twins and lots of LAGBs in coarse grain with LAGBs and new DRX grains

Fig. 6 {0002} Pole figures of MDIFed GW94 alloy MDIF for 30 passes: a 350 °C, b 400 °C, c 500 °C

Fig. 7 Relationship among average grain size, twins percentage and forging temperature of MDIFed GW94 alloy obtained from EBSD data. The region inscribes by yellow circle that reveals the twin’s percentage and average grain size at MDIF 50 passes