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The kinetics of deformation processes on the yield plateau is studied in aluminum alloy 1550. It is found out that in the general case, the Luders band fronts move discretely and only in the phase of specimen unloading. A continuous motion of the deformation fronts is possible if the relaxation rate of the applied stresses due to the test machine is higher than or equal to the rate of their decrease controlled by the internal processes at a lower scale level. The discrete motion of the Luders fronts in the 1550 alloy suggests that they are not purely switching autowaves.

We consider the regularities of a plastic flow in materials with strain-induced phase transformation in titanium nickelide and trip steel as examples. The experimental analysis of plastic deformation processes has been carried out using the technique of digital correction of speckle images, which makes it possible to describe quantitatively the behavior of plasticity fronts associated with phase transformation in the given materials. The mechanisms of formation of the Luders fronts as well as the Portevin–Le Chatelier fronts at different stages of the plastic flow are considered.

The kinetics of deformation processes at the yield plateau in the aluminum alloy 1550 studied. It is established that in the general case, the motion of the Lüders band fronts occurs discretely and only in the phase of sample unloading. Continuous motion of the deformation fronts is possible if the rate of relaxation of the applied stresses due to the test machine is greater than or equal to the rate of their decline, controlled by internal processes at a lower scale level. The discrete motion of the Lüders fronts in the 1550 alloy suggests that they are not pure autowaves of switching.

The behavior of localized plastic flow autowaves in a Fe–Ni–Cr alloy at temperatures 143 K ≤ T ≤ 420 K is considered. The temperature variation of the autowave propagation velocity is studied. It is found that, for the region of low temperatures, the autowave velocity is inversely proportional to the work hardening coefficient and the quadratic dispersion law takes place. The elastoplastic strain invariant does not depend on temperature.

The behavior of characteristics of localized plastic flow autowaves in a Fe–Cr–Ni alloy in the temperature interval of 143 ≤ T ≤ 420 K (0.34 ≤ T/ΘD ≤ 1), where ΘD = 420 K is the Debye temperature (parameter), is considered. It is shown that the product of the length and propagation rate of the autowave λVaw in this interval decreases with temperature. At the same time, the ratio of this quantity to viscosity of the photon gas in the metal in the investigated temperature interval remains almost constant. This indicates that the elastoplastic strain invariant does not depend on temperature.

General patterns of localized plastic flow development are described at linear work hardening stages of nineteen metals. Correlations between the position of the element in the periodic table of elements and the parameters of the autowave localized plastic flow have been established and discussed. The observed correlations indicate the existence of dependences of the localized plastic flow in a deformable medium on the lattice parameters of the elements and their electronic structures.

A new approach is suggested for explanation of autowave processes during plastic deformation of metals. It is based on the postulate that a quasiparticle corresponds to a localized flow autowave. Characteristics of the quasiparticle are determined, and a number of consequences from the postulate are considered. The relations have been established for the processes on micro- and macro-level in the course of plastic deformation.

Basic concepts of the autowave model of development of a localized plastic flow of solids of different natures are considered. It is shown that plastic deformation develops in a localized (at the macroscale level) way throughout the process. The form of the observed localization patterns is related to stages of strain hardening of the material. The patterns are projections of different modes of the localized plastic flow autowave on the observation surface. An elastoplastic strain invariant is introduced, which is considered as the main equation of the autowave plasticity model, and its physical nature is discussed.

The relationship between the spatial parameter of the development of a localized plastic flow (the length of the localized plasticity autowave) and the length of the deformed sample is studied. According to experiments carried out on polycrystalline samples of a zirconium alloy and commercial purity aluminum, these quantities are related to each other by a logarithmic law valid at the stage of parabolic strain hardening.

The deformation behavior of TRIP steel at the macroscopic level is experimentally investigated. It has been established that the deformation-induced austenite → martensite phase transformation is developed by shaping localized deformation fronts and can be described in terms of the propagation of the Luders and Portevin–Le Chatelier bands; therefore, the theory of autowave localized plasticity is applicable to them. On the elastoplastic transition, the transformation is realized in the form of auto-switching waves, which originate, propagate, and annihilate. With further loading of the zone of origin of auto-switching waves, they become sources of excitation autowaves.

The regularities in the inhomogeneous development of plastic deformation at the front of the Luders band at the yield plateau in Hadfield steel single crystals are considered. It has been established that the Luders front moves in jumps under these conditions. This character of motion is associated with the rearrangement of the inhomogeneous distributions of the components of the plastic distortion tensor components at the deformation front. A plausible estimate of the frequency of oscillations in the development of the Luders front has been obtained.

The plastic flow macrolocalization in single crystals and polycrystalline alloys at various stages of strain hardening is considered. The macrolocalized plastic flow at these stages is shown to be an autowave self-organization process. The ultrasound velocity is found to be an informative parameter of autowave plastic deformation.

The notions of plastic flow localization are reviewed here. It have been shown that each type of localized plasticity pattern corresponds to a given stage of deformation hardening. In the course of plastic flow development a changeover in the types of localization patterns occurs. The types of localization patterns are limited to a total of four pattern types. A correspondence has been set up between the emergent localization pattern and the respective flow stage. It is found that the localization patterns are manifestations of the autowave nature of plastic flow localization process, with each pattern type corresponding to a definite type of autowave. Propagation velocity, dispersion and grain size dependence of wavelength have been determined experimentally for the phase autowave. An elastic-plastic strain invariant has also been introduced to relate the elastic and plastic properties of the deforming medium. It is found that the autowave’s characteristics follow directly from the latter invariant. A hypothetic quasi-particle has been introduced which correlates with the localized plasticity autowave; the probable properties of the quasi-particle have been estimated. Taking the quasi-particle approach, the characteristics of the plastic flow localization process are considered herein.

The kinetics of the martensitic transformation fronts in transformation-induced plasticity (TRIP) steel was studied in relation to preliminary thermomechanical treatment using the digital image correlation method. It was found that warm rolling of steel to 40&ndash, 63% reduction significantly increases the stress of the onset of strain-induced phase transformation and changes the loading curve stages. The strain-induced phase transformation in TRIP steel occurring through the formation of L&uuml, ders and Portevin&ndash, Le Chatelier bands is shown to be an autowave process of localized plasticity. The austenite &rarr, martensite transformation at the elastic-plastic transition occurs in the form of several switching localized plasticity autowaves. At the jerky flow stage, excitation autowaves of localized plasticity are generated and propagate repeatedly until the strain-induced austenite &rarr, martensite transformation is completed. It is shown for the first time that the sources of excitation autowaves in the material are the sites of nucleation or annihilation of switching autowaves.

We consider the autowave mechanism of evolution of a localized plastic deformation of crystalline solids of different origins. It is found that localization of the plastic flow is determined by the relation between elastic and plastic phenomena in deforming materials. The origin of this relation is explained using general thermodynamic concepts. It is shown that parameters of plastic flow localization at the stage of linear strain hardening in the process of solid body deformation are closely related to characteristics of the electronic structure of metals. Inverse of the product of wavelength and velocity of the localized plasticity autowave grows linearly with the number of conduction electrons per unit cell of the metal. The obtained data directly indicate that the nature of the electron-gas contribution to hindering of dislocations is more complicated. Thus, the parameters of plastic flow localization are defined by the position of metal in the Mendeleev periodic table.

Macroscopic laws of the development of plastic flow localization autowaves in metals, alloys, alkali halide crystals, and rocks are investigated. It is shown that the characteristics of elastic and plastic waves form an elastoplastic invariant. The nature of the invariant is explained, and it is demonstrated that its existence is determined by changes in the entropy of a deformable system in the process of generation of localized plastic flow autowaves. It has been established that the main features of the deformation and deformation hardening processes can be considered as a consequence of the elastoplastic invariant.

An interpretation of the nature of the relation between elastic and plastic strains, called the elastic–plastic strain invariant, is proposed which takes into account the change in the entropy of the system during autowave generation at the stage of linear strain hardening. It is shown that this approach consistently explains the nature of the invariant and its role in the description of plasticity.

The features of the macroscopic inhomogeneity of plastic deformation in the form of autowaves with a pulsating amplitude are analyzed, and data on the localization of sources of acoustic emission at different stages of plastic flow in the stretching of fcc mono- and polycrystals are presented. The relationship between the local components of the plastic distortion tensor in the strain localization zone is traced. The role of acoustic phenomena accompanying the localization of plastic strain in the development of the process of plastic deformation is considered.

We consider the autowave mechanism of evolution of a localized plastic deformation of crystalline solids of different origins. It is found that localization of the plastic flow is determined by the relation between elastic and plastic phenomena in deforming materials. It is shown that the main parameter of deformation processes is the elastic–plastic deformation invariant, viz., a dimensionless quantity connecting quantitatively the parameters of elastic waves and self-sustained waves (autowaves) of localized plastic deformation. The correctness of this statement is verified for metals, alkali-halide crystals, and rocks. The physical origin of the invariant is explained on the basis of thermodynamic considerations.

Results of measurements of the coefficient of microwave reflection from a block of freshwater ice subjected to plastic deformation are presented. Strong fluctuations in the phase of reflection coefficient are revealed, with the extremum at an electromagnetic radiation wavelength of 1.35 cm. This wavelength corresponds to the region of localized plastic flow autowaves in crystalline media.

This paper discusses the kinetics of the fronts of localized plastic deformation in TRIP steel using a combination of DIC methods and magnetization measurements. It is shown that the kinetics of deformation fronts, which is mainly determined by the stages of the hardening curve, is consistent with changes in the phase composition. A phase transformation starts with the propagation of Luders bands and then proceeds through the formation and propagation of Portevin–Le Chatelier bands, but only in the region of increasing strain hardening coefficient. After the transition to the stage where the hardening coefficient decreases, the γ → αʹ phase transformation decays and is no longer the predominant mechanism of jerky flow. Both types of plastic instability in TRIP steel can be described using the autowave concept of localized plasticity.

In the article the deformation of different steels is analyzed using the autowave theory of plasticity. The article considers the possible use of an autowave model to formulate criteria for the structural strength of materials and elastic-plastic transition. The time and place of future fracture for steel samples are shown can be predicted before visible necking takes place by using the kinetic dependencies of localized plasticity domains at the prefracture stage. The results show that during elastic-plastic transition in lowcarbon steel, there is the break of the curve for the ultrasound velocity versus deformation, which can serve as an acoustic criterion of irreversible deformation for the pressure treatment of metals, the operation and nondestructive testing of products and structures.

Conditions have been considered for the formation of autowaves of localized plastic flow in the deformed metals upon the propagation of Luders bands in the case of the Portevin–Le Chatelier effect, and upon the formation of a neck with taking into account the differences in the microscopic mechanisms of plastic deformation in the case of these phenomena. The laws that govern the development of the localized plastic flow of metals and the role of these laws in the development of the above effects have been investigated. It has been established that the main features of the deformation characteristic of these phenomena are determined by the differences in the properties of the active media that are formed in the material upon plastic deformation. The mechanisms of the generation of different autowave modes of the localized plastic flow upon the Luders deformation, Portevin–Le Chatelier effect, and the formation of a neck in active media of different nature during deformation have been considered.

The development of macroscopic plastic flow heterogeneities in metals in the form of Chernov–Luders bands and the Portevin–Le Chatelier effect is studied. The main laws of deformation development in these two cases are found, and the kinetics of the motion of Chernov–Luders band fronts and the serrated deformation during the Portevin–Le Chatelier effect is investigated. It is shown that both versions of heterogeneities can be considered as macroscopic autowave processes of switching and excitation in deformable media.

The development of macroscopic inhomogeneities in the form of Chernov–Luders bands and serrated deformation bands (Portevin–Le Chatelier effect) in plastic metal flow is studied. For these two cases, regularities in the development of deformation inhomogeneity were established and the kinetics of motion of the fronts of Chernov–Luders bands and serrated deformation bands was studied. It is shown that the Chernov–Luders fronts and the serrated Portevin–Le Chatelier deformation can be considered as macroscopic autowave switching and excitation processes, respectively, in deformable media of different nature.

We have studied the regularities in the evolution of macroscopic nonuniformities in the plastic flow of metals in the form of the Chernov–Luders bands and the Portevin—Le Chatelier effect. The regularities in the evolution of strain inhomogeneity in these two cases have been established, and the kinetics of motion of the Chernov–Luders fronts and abrupt deformation in the Portevin–Le Chatelier effect has been analyzed. It has been shown that the Chernov–Luders fronts and Portevin–Le Chatelier jumpwise straining can be treated as macroscopic autowave processes of switching and excitation, respectively, in deformed media of various origins.

Spatial self-organization of plastic flow localization depends on the work hardening law. At the parabolic hardening stage the most important parameter of stationary dissipative structures existence is their spatial period (autowave length). This study attempts to determine the dependence of autowave spatial period on the object size under loading. The investigations were performed using commercially pure aluminum (1050A) which has prolonged parabolic hardening stage. Exponential dependence of autowave length on tested specimen size was revealed. Minimum size of tested specimen for autowave pattern occurrence has been defined.

A new approach is proposed for description of autowave processes responsible for plastic deformation localization in metals and alloys. It is postulated that to a localized flow autowave there corresponds a quasi-particle. The characteristics of the quasi-particle have been determined. The above postulate leads to a number of consequences and quantitative assessments that are considered herein. A direct relationship has been established between the processes involved in the deformation on a macro- and a microscale level.

The correlation between lattice characteristics of a deformed medium and parameters of autowaves of a localized plastic flow in metals at the stage of linear strain hardening is considered. Such correlation testifies for the existence of a close connection between elastic and plastic deformations of the medium and, more generally, between characteristics of plasticity and electronic structure of elements.

The localized plastic deformation and the law-like regularities underlying its development in solids are considered. The characteristic features of localized plasticity are analyzed for a wide range of materials. Thus a correlation is established between the products of scales and of process rates obtained for the elastic and plastic deformation. It is a favorable ground for hypothesizing causal links between the elastic and plastic deformation by introducing an elastic-plastic invariant, which is the master equation of the autowave plasticity model being developed. Localized plasticity phenomena are proposed to be addressed in the frame of autowave and quasi-particle approach.

An experimental and theoretical study of plastic shear localization mechanisms observed under dynamic deformation using the shear–compression scheme on a Hopkinson–Kolsky bar has been carried out using specimens of AMg6 alloy. The mechanisms of plastic shear instability are associated with collective effects in the microshear ensemble in spatially localized areas. The lateral surface of the specimens was photographed in the real-time mode using a CEDIP Silver 450M high-speed infrared camera. The temperature distribution obtained at different times allowed us to trace the evolution of the localization of the plastic strain. Based on the equations that describe the effect of nonequilibrium transitions on the mechanisms of structural relaxation and plastic flow, numerical simulation of plastic shear localization has been performed. A numerical experiment relevant to the specimen-loading scheme was carried out using a system of constitutive equations that reflect the part of the structural relaxation mechanisms caused by the collective behavior of microshears with the autowave modes of the evolution of the localized plastic flow. Upon completion of the experiment, the specimens were subjected to microstructure analysis using a New View-5010 optical microscope–interferometer. After the dynamic deformation, the constancy of the Hurst exponent, which reflects the relationship between the behavior of defects and roughness induced by the defects on the surfaces of the specimens is observed in a wider range of spatial scales. These investigations revealed the distinctive features in the localization of the deformation followed by destruction to the script of the adiabatic shear. These features may be caused by the collective multiscale behavior of defects, which leads to a sharp decrease in the stress-relaxation time and, consequently, a localized plastic flow and generation of fracture nuclei in the form of adiabatic shear. Infrared scanning of the localization zone of the plastic strain in situ and the subsequent study of the defect structure corroborated the hypothesis about the decisive role of non-equilibrium transitions in defect ensembles during the evolution of a localized plastic flow.

Considerable attention has been given to the investigation of the distinguishing features of localized plastic deformation at the stage of linear work hardening. The study was made for a wide range of metals and alloys differing with respect to material state and crystal lattice type. The process of deformation localization is inherently a wave process characterized by wavelength and wave propagation velocity. It is found that the wavelength of localized deformation is related to the structural elements of the material. The dynamics and kinetics of the process of deformation localization at the pre-failure stage have been examined and the process parameters are related to the electronic properties of metals.

The dependence of the localized plasticity autowaves on the Debye parameter (Debye temperature) has been analyzed for nineteen different metals. Characteristics of autowaves are determined using speckle photography method. It is shown that this experimentally established linear relationship is a consequence of the previously introduced elasto-plastic deformation invariant, which connects parameters of elastic and plastic processes in a deformable medium.The dependence of the localized plasticity autowaves on the Debye parameter (Debye temperature) has been analyzed for nineteen different metals. Characteristics of autowaves are determined using speckle photography method. It is shown that this experimentally established linear relationship is a consequence of the previously introduced elasto-plastic deformation invariant, which connects parameters of elastic and plastic processes in a deformable medium.

The localized plasticity development was studied for a wide range of pure metals and alloys in single-crystal and polycrystalline state as well as nonmetallic materials, alkaline halide crystals, ceramics and rocks. Using photographic and digital versions of speckle photography, the localization of plastic flow in the test samples was investigated on specially designed units having high spatial and temporal resolution. According to the analysis given here, the different stages of plastic flow are related both qualitatively and quantitatively.

The localized plasticity development was studied for a wide range of pure metals and alloys in single-crystal and polycrystalline state as well as nonmetallic materials, alkaline halide crystals, ceramics and rocks. Using photographic and digital versions of speckle photography, the localization of plastic flow in the test samples was investigated on specially designed units having high spatial and temporal resolution. According to the analysis given here, the different stages of plastic flow are related both qualitatively and quantitatively.

A correlation between the characteristics of localized plasticity autowaves and the Debye temperature of crystalline lattice in 19 metals has been analyzed. It is shown that this experimentally established linear dependence follows from the previously introduced elastoplastic invariant of deformation that relates the parameters of elastic and plastic processes in a deformable medium.

The patterns of plastic flow localization in high-manganese γ-Fe FCC single crystals undergoing the twinning while stretched are obtained by the experimental procedure of double-exposure laser speckle photography, which permits accurate in situ measurement of plastic distortion tensor components during specimen loading and analysis of local strain distributions over the tested specimen. Basic spatiotemporal features of strain localization at the stages of yield plateau, easy glide, and linear hardening are established. The type of ordered space-time arrangement of localization nuclei, i.e. the type of localized deformation wave, which is observed for the respective flow stage (yield plateau, easy glide, linear and parabolic work hardening), is determined by the acting law of work hardening. The velocity of strain localization sites moving upon stretching is determined. Conditions under which plasticity autowaves appear in the strained medium are discussed. It is demonstrated that the local strain distributions in the case of twinning are similar to those due to dislocation glide.

The deformation of materials with unstable phase structure such as titanium nickelide (nitinol) and steel with transformation induced plasticity (trip-steel) was studied within the framework of the autowave theory. It was established that at the initial stages of deformation a strain induced martensitic phase transformation occurs in both materials, which is realized as switching autowaves of localized plastic deformation. In nitinol it occurs completely, while in TRIP steel the remaining unstable austenite under further deformation expose a transformation similar to the Portevin–Le Chatelier effect with formation of waves of excitation of localized plastic deformation.

Plastic strain localization patterns in compression-strained alkali halide (NaCl, KCl, and LiF) crystals have been studied using a double-exposure speckle photography technique. The main parameters of strain localization autowaves at the linear stages of deformation hardening in alkali halide crystals have been determined. A quantitative relationship between the macroscopic parameters of plastic flow localization and microscopic parameters of strained alkali halide crystals has been established.

The localization behavior of plastic flow was investigated for a range of pure metals and alloys. The localized plastic flow is regarded as an autowave process having a fixed set of features, i.e. propagation rate, wave number and dispersion law. Using the method of speckle photography, the autowave propagation rate has been determined experimentally for the stage of linear work hardening. Moreover, a dispersion relation of quadratic form and wave number dependencies of phase and group rates have been derived for localized plastic flow autowaves. A detailed quantitative comparison is made of the phase and group rates of the autowaves. This suggests that the two types of wave rates are closely related.

Patterns accompanying the development of a localized plastic flow in solids are considered. A correlation between products of the linear and rate parameters of elastic and plastic flows is revealed by analyzing localized plastic flows in metals and nonmetals. A relationship between the parameters of elasticity and plastic flow is hypothesized. A relationship between patterns in plastic flow and quantum-mechanical parameters is found.