L. B. Zuev, S. A. Barannikova, S. V. Kolosov

MACROSCALE PLASTICITY PARAMETER OF METALS AND ALLOYS

It is shown that plastic flow in solids emerges in a localized manner at a macroscopic scale of ~10−2 m. Localized plastic flow zones form patterns of localized strain, which are the projection of the autowave processes of plastic flow, developing in the bulk of the material, onto the specimen surface under study. The speckle photography method was chosen as a source of information about the kinetics of plastic deformation. A common feature of localized plastic flow in solids is the elastic-plastic invariant of deformation, which combines the typical characteristics of localized plastic flow autowaves with those of elastic waves in a crystal lattice. The invariant ratio is defined for nearly forty various materials (BCC, FCC, and HCP metals and alloys, alkali-halide crystals, ceramics, and rocks) under active tension and compression in a temperature range of 143 to 420 K. The origin of the invariant and its relation to other physical characteristics of the crystal lattice, e.g. the Debye temperature, is discussed in physical terms. Besides, numerous corollaries of the elastoplastic invariant are derived, enabling one to describe adequately the regularities of plastic flow. This, in turn, makes it possible to consider the elastic-plastic invariant of deformation as the main equation of the currently developing autowave approach to the physical theory of plastic deformation.

Acknowledgments: This work was supported within the framework of the state assignment for the ISPMS SB RAS, project No. FWRW-2021-0011.

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