Structural transformations in the Al85Ni6.1Co2Gd6Si0.9 amorphous alloy during multiple rolling

Specific Features of Structure Transformation and Properties of Amorphous-Nanocrystalline Alloys

“…The authors related the nanocrystal formation in shear bands to an increase in the local mass transfer rate in these regions. Similar results were obtained in [89], where the authors demonstrated the formation of Al nanocrystals in rolled amorphous Al 85.1 Ni 6 Co 2 Gd 6 Si 0.9 alloy at room temperature. Figure 14a shows the microstructure of an alloy deformed by multiple rolling.…”

“…This depends, particularly, on the diffusion rate and, of course, cannot be provided in all materials. Severe plastic deformation turned to be the other method, which is effective in view of the nanocrystallization initiation [84,89,102,[109][110][111][112][113]. The use of this method enabled obtaining an amorphous-nanocrystalline structure in alloys where it is not formed under the crystallization by heat treatment [112,113].…”

Modification of atomic mobility in a Ti-based bulk metallic glass by plastic deformation or thermal annealing

“…It was reported recently that cold-rolling can induce the formation of nano-crystallites in bulk metallic glasses [80], especially in NiTi [81] and Al 85 Ni 6.1 Co 2 Gd 6 Si 0.9 [82]. In contrast no crystallization was detected after cold-rolling in Zr 60 Cu 30 Al 10 [83], Zr 55 Al 10 Ni 5 Cu 30 [84], Cu 47.5 Zr 47.5 Al 5 [85] and Zr 55 Cu 40 Al 5 [44].…”

Al-based amorphous alloys: Glass-forming ability, crystallization behavior and effects of minor alloying additions

“…However, severe plastic deformation (SPD), such as rolling, tension and torsion, is an alternative approach to stimulate crystallization. From in-situ tensile straining in the TEM on amorphous Al 88 Y 7 Fe 5 [26] and the multiple rolling on Al-Ni-Co-Gd-Si [27], nanocrystals were observed to form preferentially in shear bands presumably due to the enhanced atomic mobility from the marked increase in the excess volume inside the shear bands. However, observations following the high pressure torsion applied to an Al 90 Y 10 amorphous alloy indicated that there was no correlation between the location of nanocrystals and the position of shear bands [28] and Jiang et al reported that in the tensile region of the amorphous Al-Fe-Gd sample under bending, nanocrystals formed only at the fracture surface, which was likely to be due to the adiabatic heating [29].…”