Gordienko Y. Scale-invariant behavior of defect substructures under conditions of localized plastic deformation of metals

Defect substructures in metals under conditions of localized plastic deformation exhibit qualitative features of correlated collective (synergetic) behavior of defects with emergence of collective (hydrodynamic) modes of deformation in the form of non-crystallographic localization zones with the qualitative features of self-similarity. The scale-invariant behavior of surface manifestation of defect substructures under conditions of localized plastic deformation is characterized quantitatively by: presence of geometric self-similarity in the wide range of scales, its stability with deformation; spatial and orientational localization. The emergence of extreme conditions for qualitatively new collective (hydrodynamic) modes of deformation due to correlations of crystal lattice defects and their aggregations at different scale levels was quantitatively confirmed by MD-simulations on the basis of Kolmogorov-Smirnov test, as well as by the moment and bootstrapping analyses, i.e. by the drift of defect concentration distributions over an ensemble of samples -- from the normal distribution towards the region of extreme values distributions. From a practical point of view, the developed method of fractal analysis of deformation structures can be used to obtain differential information about the deformation pre-history of metal, to predict the occurrence of the critical state of materials during evolution of the defect substructure in materials and identify areas of spatial and orientational localization of deformation and mechanical damage. The proposed method of computer simulation allows to determine areas of the control parameters corresponding to occurrence of the defect substructures with the controlled properties, which are suitable for use as functional nano- and micro- devices, such as sensors for damage estimation, membranes, and catalysts.