The study of energy balance in metals under deformation and failure process

Influence of metal texture and loading rate on heat release under quasi-static tension

“…The obtained results supplement the data on the influence of the structure of metallic materials on the energy balance during plastic deformation and confirm the current understanding that the accumulation of latent energy in the process of plastic deformation is due to the evolution of defects at various structural levels. Note that existing attempts at theoretical description using the energy balance equations for plastic deformation have not yet presented a model that allows one to take into account the diversity, relationship, and hierarchy of plastic flow mechanisms in polycrystalline metals and alloys [7,8,23,24,37,38]. In our opinion, a physically reasonable derivation of the constitutive equations for elastoplastic deformation of materials that takes into account the accompanying phenomena (structural rearrangement, dissipation, thermoelastic effects) should be based on methods of the thermodynamics of irreversible processes [1][2][3][4][5][6], with further detailing of the contributions of micromechanisms, such as dislocations, disclinations, twins, point defects, and stacking faults, and the interaction of defects at the meso-scale of the structure.…”

“…For example, the results of experimental studies of heat release processes during the testing of copper, magnesium alloy, titanium, steel, and aluminum alloys [7,[13][14][15] have demonstrated a significant dependence of heat release intensity on strain rates under conditions of quasi-static tension in metals and alloys, with no significant effect on the stress-strain diagram. Moreover, the elements of the energy balance strongly depend on the deformation history, which leads to various mechanisms of plastic deformation in the tested metallic material [15][16][17][18][19][20][21][22][23]. It has been shown in [15][16][17] that an analysis of the effect of heat generation during plastic deformation allows an estimation of the fraction of latent heat due to phase transformation.…”

“…The dependence of the Taylor-Quinney coefficient on dynamic loading and its correlation with deformation micromechanisms has also been reported for different materials [18][19][20]. Thermal measurements of the fraction of plastic work converted to heat have also been used successfully in the study of energy storage and dissipation in low-cycle fatigue tests of metals and alloys [21][22][23].…”

Challenges and Accomplishments in Mechanical Testing Instrumented by In Situ Techniques: Infrared Thermography, Digital Image Correlation, and Acoustic Emission

“…Low-amplitude continuous signals, comparable to the background electric noise, are the most common signatures of plastic deformation due to dislocation slip [24], which not only dominates the strain hardening behaviour during the monotonic tensile or compressive test but is of crucial significance for the evolution of the microstructure in the plastic zone ahead of the propagating fatigue crack. Moreover, it is plastic work that determines the heat dissipation in the cyclic plastic zone [73][74][75][76]. In addition, a wealth of powerful signal processing techniques have been developed recently for unveiling and handling low-amplitude signals buried in the background noise, provided the waveform is continuously recorded in a sufficiently wide frequency range (see [69,71] and literature therein).…”

A novel algorithm for crack path identification based on infrared images

“…To get a better understanding of the thermodynamics of underlying processes, it is necessary to recover the properties of the heat sources. This is commonly achieved by solving the heat equation for the heat source function   , , Q x y t [8,12]. The general structure of this equation in Cartesian (x,y) coordinates reads as…”