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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.

The kinetics of deformation processes at yield plateau in materials with dislocation and martensitic mechanisms for the implementation of shear processes at the microscopic level is studied. In both cases, the formation and propagation of switching autowaves occur, which are represented by the fronts of localized plastic deformation. Autowave velocities nonlinearly depend on the loading speed. It is established that the nature of nonlinearity is the same for both materials studied.

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 formation and propagation of strain-induced phase transformation bands were studied in TRIP steels obtained under various thermomechanical processing conditions. The phase transformation during the pseudo-plateau stage is shown to occur as switching autowaves that propagate in the form of the Luders bands. After the annihilation of switching authowaves in the austenite state, the strain hardening is manifested by excitation autowaves being the Portevin–Le Chatelier fronts (PLC). Hot rolling to 63% reduction allows one to avoid the jerky flow stage and the PLC bands. The generation and propagation of martensite transformation bands are evident from the appropriate phase distribution collected via the magnetic measurements.

In this work, we analytically and numerically investigate the types of stationary gasdynamic waves formed in a heat-releasing medium with isentropic (acoustic) instability. As the mathematical model, the system of one-dimensional gasdynamic equations is used, in which the heating and cooling processes are taken into account using the generalized heat-loss function. Our analysis reveals that the type of stationary structures depends on their velocity W and heating/cooling processes acting in the medium. In an isentropically unstable medium, it is shown that the type of structures depends on whether they propagate faster or slower than the critical velocity Wcr. If W > W c r, a shock wave is formed, in which, after the shock-wave compression, the gas expands to a stationary value. The characteristic size of the expansion region depends on the characteristic heating time, which is determined by the specific type of the heat-loss function. If W < W c r, the shock wave turns out to be unstable and decays into a sequence of autowave (self-sustaining) pulses. The amplitude and velocity ( W = W c r) of the autowave pulse, found analytically in the article, are also determined by the type of the heat-loss function. The comparison of analytical predictions of the developed method with the results of nonlinear equation previously obtained using the perturbation theory, as well as with the numerical simulations, confirms the high accuracy of the method.

The paper presents the structure and nature of plastic deformation macrolocalization in metastable austenitic-martensitic steel in relation to preliminary thermomechanical processing. Preliminary processing affects the amount of metastable austenite, staging and type of deformation curves, evolution of localized plastic deformation autowaves. It is shown that, during TRIP steel deformation n, one type of autowaves (switching) is changed to another (excitation). The autowave transformation mechanism has been established, in which nucleation sites of switching autowaves are sources of excitation autowaves.The paper presents the structure and nature of plastic deformation macrolocalization in metastable austenitic-martensitic steel in relation to preliminary thermomechanical processing. Preliminary processing affects the amount of metastable austenite, staging and type of deformation curves, evolution of localized plastic deformation autowaves. It is shown that, during TRIP steel deformation n, one type of autowaves (switching) is changed to another (excitation). The autowave transformation mechanism has been established, in which nucleation sites of switching autowaves are sources of excitation autowaves.

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 results of acoustic parameter measurements in a deformed material with simultaneous recording of autowave patterns of localized plastic deformation for low-carbon steel 1008 are presented. Specimen deformation affects both the ultrasound velocity increase and the evolution of autowave patterns. The first kink corresponds to the elastic-plastic transition and the formation of switching autowave. The second kink and collapse of the localized deformation autowave correspond to material fracture.

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 paper studies the deformation behavior of nitinol in a superelastic state at the macroscopic level. It has been established that both the direct phase transformation B2→B19′ during loading and the reverse phase transformation B19′→B2 during unloading are realized through formation of moving fronts, which are localized plastic deformation switching autowaves. The relationship between autowave propagation velocity during loading and the gripping device speed is investigated.

The occurrence of autowaves at the interface as a result of a first-order phase transition had been examined. The linear analysis of a system of the equations for a liquid which contains two components shows that a phase transition at the interface can give rise to autowaves. A spectrum of these autowaves depends on parameters of the system. For a special case of the system parameters an analysis is made of the dependence of the spectrum of autowaves from a temperature gradient the interface. We show that as a result of a interface instability in the bulk solid phase there are various periodic structures of distribution of the component concentration. Surfaces of equal concentration for the spectra of the autowaves are built. A qualitative and quantitative comparison of the numerical calculations with experimental data is made.