Nanodipoles of Partial Disclinations and Strain Localization Mechanism of Nanostructured Materials in the Elastic Region

Аннотация

In the course of severe plastic deformation of nickel in the Bridgman anvils, a phenomenon of strain localization is observed in the region of elastic distortions, which is accompanied by the formation of reorientation nanobands with an elastic crystal lattice curvature of hundreds of deg/μm and nanodipoles of partial disclinations as the defects of elastically deformed medium and carriers of elastic shears and rotations at the front of nanoband propagation. A theoretical analysis is performed of the elastically stressed state and energy of these defects, including the case of their transformation into more complex ensembles of interconnected disclinations. Using the results obtained and the data of an MD investigation of dynamic vortex defects formed in the region of elastic distortions, the mechanisms of strain localization in this region in the stages of nucleation and propagation of these nanobands are proposed.