Fig. 1 Schematic illustrations of a, b MDIF and UDIF processes, c macroscopic morphology of forged samples after 50 passes, d the position of microstructural and tensile samples machined out from the forged sample .

Fig. 2 Optical and SEM microstructures of GW94 alloy and their EDS analysis, respectively: a-c the as-cast, d-f solutionized samples. EDS results of the inscribed areas selected in c, f .

Fig. 3 Optical microstructure evolution of GW94 alloy with different forging passes: a MDIF9, b MDIF29, c MDIF50, d, UDIF9, e UDIF29, f UDIF50 .

Fig. 4 The inverse pole figure (IPF) maps and corresponding boundary misorientations maps of the GW94 alloy after MDIF process: a, d MDIF9, b, e MDIF29, c, f MDIF50. Here, g-k are the enlarged IPF maps selected in a, b, c, e, respectively, showing the twins and the formation of sub-GBs and DRXed grains by CDRX .

Fig. 5 The inverse pole figure (IPF) maps and corresponding boundary misorientation maps of the GW94 alloy after UDIF process: a, b UDIF9, c, d UDIF29, e, f UDIF50. Here, g-i are the enlarged IPF maps selected in a, b, c, respectively, showing the formation of sub-GBs along deform GBs and DRXed grains .

Fig. 6 Obtained pole figures of the GW94 alloy after MDIF and UDIF process which reveal in sequence as a-c represent the MDIF9, MDIF29, and MDIF50 samples, respectively, whereas d-f represent UDIF9, UDIF29, and UDIF50 samples, respectively .