Two-level nanostructural states in metal materials with BCC lattice after deformation by torsion on Brigeman's anvils

The results of electron microscopy studies of two-level nanostructural states (submicrocrystals of about 100 nm in size with an internal nanocrystalline structure with nanocrystal sizes of about 10 nm and crystal lattice curvature of hundreds of deg./μm), which are formed in undoped Ta and alloys based on V and Mo-Re during deformation by torsion on Bridgeman anvils, are generalized. As a formation mechanism of these states, a mechanism is proposed for the quasi-viscous motion of nanodipoles of partial disclinations controlled by flows of nonequilibrium point defects in fields of high local pressure gradients. It is shown that the evolution of microstructure with an increase in deformation degree consists in an increase in volume fraction of a two-level nanostructural state and leads to a » 3-4-fold increase in microhardness of deformed samples with maximum values in the interval H_m » (E/27-E/32).The main physical factors and conditions of formation of these states during plastic deformation of submicro- and nanocrystals are discussed.

Keywords

Authors

References