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A comparative analysis of typical stress-strain diagrams obtained for in-plain shear of the 25 unidirectional and cross-ply reinforced polymer matrix composites under quasi-static loading was carried out. Three of them were tested in the framework of this study, and the experimental data on other materials were taken from the literature. The analysis of the generalized shear-strength curves showed that most of the tested materials exhibit the similar deformation pattern depending on their initial shear modulus: a linear section is observed at the beginning of loading, whereas further increase of the load decreases the slope of the curve reaching the minimum in the failure point. For the three parameters (end point the linear part, maximum reduced deviation of the diagram, tangent shear modulus at the failure point) characterizing the individual features of the presented stress-strain diagrams, approximating their dependences on the value of the reduced initial shear modulus are obtained. At the characteristic points of the deformation diagrams, boundary conditions are determined that can be used to find the parameters of the approximating functions. A condition is proposed for determination of the end point of the linear section on the experimental stress-strain curve, according to which the maximum deviation between the experimental and calculated (according to Hooke’s law) values of the shear stress in this section is no more than 1%, thus ensuring rather high accuracy of approximation on the linear section of the diagram. The results of this study are recommended to use when developing universal and relatively simple in structure approximating functions that take into account the characteristic properties of the experimental curves of deformation of polymer composite materials under in-plane shear of the sheet. The minimum set of experimental data is required to determine the parameters of these functions.

A new model for the asymmetrical rolling is proposed to calculate the minimum rollable thickness simply and fast by the slab method. The calculation formulas of the rolling pressure, the rolling force, the critical roll speed ratio and the critical front tension under different deformation zone configurations are proposed, and the deformation zone configuration - rolling parameters relationship diagram is given and analyzed. The results show that the minimum rollable thickness can be reached when the rolling parameters keep the deformation zone configuration as cross-shear zone + backward-slip zone (C+B) or all cross-shear zone (AC). The calculation formulas of the minimum rollable thickness and the required rolling parameters for different deformation zone configurations are proposed respectively. The calculated value is in good agreement with the experimental results.

The ability to use common computational thermodynamic and kinetic tools to study the microstructure evolution in Inconel 625 (IN625) manufactured using the additive manufacturing (AM) technique of laser powder-bed fusion is evaluated. Solidification simulations indicate that laser melting and re-melting during printing produce highly segregated interdendritic regions. Precipitation simulations for different degrees of segregation show that the larger the segregation, i.e., the richer the interdendritic regions are in Nb and Mo, the faster the δ-phase (Ni3Nb) precipitation. This is in accordance with the accelerated δ precipitation observed experimentally during post-build heat treatments of AM IN625 compared to wrought IN625. The δ-phase may be undesirable since it can lead to detrimental effects on the mechanical properties. The results are presented in the form of a TTT diagram and agreement between the simulated diagram and the experimental TTT diagram demonstrate how these computational tools can be used to guide and optimize post-build treatments of AM materials.

Novel Cu–24Pb–xAl alloys with dispersed and rodlike Pb-rich secondary phases (PSPs) were designed and prepared with the guidance of CALPHAD. Through primary binary-phase diagram analysis and thermo...

The method of forming directional diagrams (RD) with the possibility of controlling it in space is described. The method of forming of the object location detection zone of complex shape in the transmitter-receiver optical system with the help of fiber-optic cables (OIC) is substantiated and created. The problem of a circular field of view of a multi-channel optoelectronic system (ECO) creating, designed for advanced high-speed objects at short distance detection has been solved. According to the results of laboratory tests of the developed ECO model is established that in the working range of distances of a location of 0,5 ... 10,0 m reliable detection of the target high-speed and high-precision registration of object in all DS directions is reached.

Effective transport coefficient (ETC) of particulate composites is a crucial parameter in many industrial applications. ETC is subject to many microstructural parameters of the system at different scales. In this work, stochastic reconstruction is applied to study possible microstructure configurations between two selected systems. The initial system is configured to a microstructure with overlapping discs agglomerates of monodisperse diameter D = 12 pixels; the final system is configured to a particulate system of monodisperse diameter D = 1 pixel. Easy but powerful diagrams are presented as a quick design tool. The diagram user only requires the determination of two statistical magnitudes: probability of the neighbor connectivity, and infinite cluster, both statistical functions are detailed in the manuscript. This particulate composite information is defined from microstructure images. Proposed diagrams allow the user to get a position in a “map” that describes how ETC magnitude change according to: 1) size of the agglomerate diameter, 2) phase surface fraction, 3) mono-distributed and poly-distributed configuration, and 4) matrix phase or dispersed phase condition as the conductive phase. The diagram user can immediately obtain a full panorama without solving complex equations, which would let to make decisions about the modification of the geometric structure of the particulate composite. The microstructures studied are delimited to biphasic, isotropic particulate composites. The experimental validation of the diagram's effectiveness with particulate composites from the literature is accomplished.

Advanced high-strength steels (AHSSs) are often illustrated in the steel strength–ductility diagram, which is also known as the “banana chart” due to the distribution trend of the tensile properties of the steel family. Both academia and industry frequently refer to such a diagram not only to categorize the evolving AHSS generations but also to direct future development objectives. Nevertheless, with various new AHSSs developed in recent years, the “banana chart” is considered too simplified to represent the sophisticated tensile properties of these AHSSs, especially when some practical conditions are taken into account. Therefore, this work focuses on investigating how the temperature and strain rate affect the tensile properties of selected AHSSs and correspondingly shift their distributions in the “banana chart.” Explanations and discussions on the possible mechanisms behind these effects are also presented.

The existing processes for the preparation of grain molasses are described. The flow diagrams for functioning of the most common installations for its production are shown. A functional and morphological analysis was performed, a morphological matrix was developed, and the most rational version of the design layout and process flow diagram of the installation was selected. The functional and morphological diagram of the installation for the preparation of grain molasses constructed using the methods of the theory of solving inventive problems is provided.

Besides revealing excellent mechanical properties, compositionally complex alloys are also very promising candidates for applications in heterogeneous catalysis. The opportunity provided by the tremendously large composition phase space to explore new materials and tune the materials properties in the materials design cycle is, however, intrinsically coupled with the challenge of controlling surface segregation, which is generally more severe in multicomponent alloys as compared to simpler systems. We demonstrate this by computing the surface phase diagram of two candidate compositionally complex catalysts. Significant surface segregation is found even at very high temperature and this can strongly affect the catalytic properties of these alloys. We explain the observed phase stabilities in terms of segregation energies and rationalize the segregation trends with canonical models. Finally, we propose a set of descriptors accessible with first-principles calculations that allows to quickly incorporate the evaluation of the segregation during the alloy design process. © 2021 The Author(s)

Potential-pH (E-pH) diagrams are usually built from thermodynamic databases available in the literature or from specific software. However, depending on the conditions and the chemical species defined for elaborating a diagram, they may present completely different immunity, passivation, and corrosion domains. In order to obtain a result closer to a real system, experimental E-pH diagrams can be built from polarization curves obtained in the evaluated conditions. This work discloses the construction of a diagram for the Nb-H2O system at 25°C from theoretical study and the specific selection of chemical species in the solutions through computer simulations. The polarization curves for the construction of the experimental diagram were gathered without the use of buffer solutions and under pH monitoring in the solution bulk throughout all assays. The methodology proposed was considered adequate because, from experimental data, a final result compatible with the classic diagram for the Nb-H2O system and the excellent corrosion resistance of niobium in aqueous media were achieved.

An analytical formula for a smooth description of the tension diagram of EK-181 steel and a method for rearranging the diagram when changing the direction of deformation are proposed for the first time. The process of straightening a quarter of an annular sample and further stretching is numerically modeled. It is shown that the conditional yield strength of the material of the straightened sample is 7.5% less than the actual conditional yield strength of steel. It is shown that the test for pure bending of a cantilever sample in the form of a semicircle with the processing of the bending diagram (by analogy with GOST 3565–80 for torsion) provides an estimate of the conditional yield strength which is 32% higher than the actual yield strength. The possibility of numerical reconstruction of the tension diagram from the diagram of pure bending of a cantilevered semi-ring sample is proved. It is shown that this procedure really gives the value of the conditional yield strength of steel EK-181 with a tolerance for the residual deformation of 0.2%. The analysis of the test procedure for the rings of fuel element cladding and the proposed algorithm for determination of the conditional yield stress of the ring material is carried out. Attention is drawn to the arbitrariness of the choice of the designed load on the two-stage diagram of the diametrical tension of the ring and to the lack of scientific substantiation of the possibility of determining the yield stress on the second part of the diagram. It is shown that this method in the current form contradicts GOST for tensile testing due to the absence of a base with a uniform stress state on the ring. Therefore, the considered method is not recommended for determining the values of the conditional yield strength suitable for strength calculations.

У овом раду детаљно су обрађена три електромоторна погона топлане на природни гас. Описан је начин избора одговарајућег фреквен­тног регулатора, сензора и програмабилног логичког контролера за сваки електромоторни погон посебно. Такође, у практичном делу рада формиран је и образ­ложен лествичасти дијаграм за управљање електро­моторним погонима топлане на природни гас.

The C–O–H2 ternary diagram is presented to characterize the carbon activity in equilibrium with gas mixtures containing CH4, CO, CO2, H2O, and H2 at different temperatures and pressures. The three reactions for carbon deposition from CH4, CO, and CO + H2 are considered jointly, and the combined equilibrium carbon activity is calculated. The lines on the diagram show a set of gas compositions that is in equilibrium with a defined value of carbon activity at a given temperature and pressure. It was possible to verify that carbon activity in equilibrium with the direct reduction process gas of Midrex is 0.15 and of Energiron ZR is 8.5, explaining the higher carbon content in the reduced iron for the latter. In the case of steam reforming of methane and methanol, carbon activity in usual industrial conditions are of 0.35 and 0.73 respectively. Finally steam reforming of ethanol was evaluated and it was shown that carbon deposition is expected at 240 °C but would be avoided at temperatures of 500 °C and higher in equilibrium conditions. The proposed diagram could be useful in many chemical, catalytic, and metallurgical processes for study or prevention of carbon formation.

Upsetting tests of VTI-4 alloy samples at a temperature of 1010°C under high-rate loading have been carried out. On the basis of the test results, the elastic modulus, as well as the level of axial and radial plastic strain within the end zone and within the central zone at each stage of loading, has been determined. Criteria are proposed for the correspondence between finite element simulation and experimental data, and a model diagram is plotted for the deformation of the VTI-4 alloy at a temperature of 1010°C and a deformation rate of 2.5 s–1. As a result of the simulation, a relationship between the material structure obtained during high-rate upsetting and the stress-strain state within different zones has been determined.

The state of elastic rolling of the wheel is considered as a special manifestation of the highly developed evolution of the plastic contact of rolling friction. It is shown that for the material point of contact of smooth rolling surfaces, their initial elasticity forms a pair of elastic roughnesses – the sliding friction model. The Carter’s diagram is analyzed and its interpretation is given as an analog of the metal tension curve. This diagram is transformed to a structural-energy diagram of the sliding friction coefficient (evolution) of the rubbing surfaces. The conclusion is made about the mutual generality of the Carter’s equation and the equation of the energy balance of friction. The evolution of the structure of the rolling contact to the ideal nano-state, adequate to the state of the ideal solid, is justified. The possibility of the existence of an almost ideal thermodynamic cycle at the rolling contact and the maximum efficiency of the energy transformation is shown. In this state, we make up one mechanical (nano) quantum of the self-organized dynamic dissipative structure of the elementary friction contact with minimal contact shift (creep). This actually determines the real performance characteristics of the heavy-loaded Hertz contact of real engineering systems.

The continuous cooling transformation (CCT) diagram of 30CrMo steel simulated by compact strip production process was constructed. And the effect of austenite deformation on the CCT behaviour was i...

x,T-phase diagram of the solid solution of multiferroic PbFe1/2Ta1/2O3 with ferroelectric PbTiO3 for the 0 ≤ x ≤ 0.3 compositional range was plotted for the first time using the data of dielectric,...

The uncertainty in the prediction of machining stability increases with the increasing flexibility of the workpiece. The past research showed that the process cannot be stabilized even using the la...

Using published and presently calculated diffusivities, a reliable and self-consistent atomic mobility description of the liquid and fcc phases in a Nd-Fe-B system is established by DIffusion-Controlled TRAnsformation software. Based on the obtained atomic mobility-coupled thermodynamic descriptions of the Nd-Fe-B system, a wheel speed-dependent solidification diagram for a model Nd2Fe14B alloy is constructed, which allows us to examine the influence of wheel speed on the solidification behavior of the quenching Nd2Fe14B alloy. According to the theoretically obtained solidified microstructures and their relationship with the magnetic properties, the optimal wheel speed when melt-spinning the quenching Nd2Fe14B ribbons is determined to be 35 m/s. The experimental microstructural characterizations and magnetic hysteresis loop measurements confirm that the ribbon prepared at a wheel speed of 35 m/s exhibits the best comprehensive magnetic properties because the remaining bcc-Fe phase is significantly suppressed and the main Nd2Fe14B phase was well refined to an ultrafine-grained microstructure. The grain refinement mechanism of the main phase in the ribbons is also described.

Numerical methods used to calculate strength are based on energy approaches and minimization of functionals of one type or another. Yet the model of a material is limited to stable processes of deformation. As a result, a considerable number of deformation properties related to realization of the softening stage in materials of structural elements remains unaccounted for. To describe fracture as a new phenomenon in the behavior of structures, one needs to apply newer experimental and calculational approaches. The article cites results of modelling and experimental notions on the stage of softening in materials and its role in determining their durability. It is proposed to define the durability of a structurally inhomogeneous material as its capacity of equilibrium deformation beyond its ultimate strength under specified loading conditions. That reflects nonlocality of criteria for the failure of the material, their dependence both on its own properties and the geometry of a structural element. Complete stress-strain diagrams for structural materials of various classes and examples on how the softening stage is realized in structural materials are given.

The kinetics of fatigue crack growth has been studied in tensile testing of compact steel tensile specimens (S(T)-type) in the middle section of the kinetic diagram of fatigue fracture (fatigue crack growth diagram) under regular and irregular loading with different asymmetry and maximum load values. The samples were tested on a BISS Nano-25kN servo-hydraulic machine. Standard loading spectra typical for different technical objects exposed to alternating loading during operation were used. The values of the crack growth rate per cycle in the loading block were obtained. Parameters for assessing the character of irregular loading and crack closure, namely, the irregularity factor and crack closure coefficient were proposed. When calculating the effective value of the range of the stress intensity factor (SIF) at the crack mouth, we propose also to take into account the loading irregularity in addition to the closure coefficient. With this approach, the obtained fatigue crack growth diagrams can be grouped into one equivalent curve, which is characteristic of regular loading with R = 0. Moreover, grouping of the fatigue crack growth diagrams provided the use of unified parameters when calculating the crack growth kinetics, regardless of the type and parameters of loading, which rather simplified the crack growth determination. The fatigue crack growth life was predicted taking into account the crack «closure» and the nature of loading according both to the approach developed by the authors and by cyclic calculation method (cycle-by-cycle). All the data obtained are tabulated and classed according to the type of loading. The calculation results and experimental data showed good convergence, which was confirmed by the high values of the correlation coefficient.

Currently, multiple emulsions via liquid-liquid phase separation in ternary polymer solutions have sparked considerable interest because of its remarkable potential in physical, medical, and biological applications. The transient "onion-like" multilayers are highly dependent on the evolution kinetics, which is challenging to be scrutinized in experiments and has not yet been fully understood. Here, we report a thermodynamically consistent multicomponent Cahn-Hilliard model to investigate the kinetics of multiple emulsions by tracing the temporal evolution of the local compositions inside the emulsion droplets. We reveal that the mechanism governing the kinetics is attributed to the competition between surface energy minimization and phase separation. Based on this concept, a generalized morphology diagram for different emulsion patterns is achieved, showing a good accordance with previous experiments. Moreover, combining the analysis for the kinetics and the morphology diagram, we predict new emulsion structures that provide general guidelines to discovery, design, and manipulation of complex multiphase emulsions.

Systematic investigations on the fatigue strength of heat treated sintered steels with notched specimens are barely found in the literature, especially at stress ratios other than R = −1. For that ...

The MnS–Tb2S3 phase diagram has been plotted by using physico-chemical methods of analysis. This diagram refers to the transition type from the eutectic system MnS–Gd2S3 to the systems with the formation of intermediate compounds. Two MnTb4S7 and MnTb2S4 complex sulfides are formed in the MnS–Tb2S3 system. The thermal effects of solid-phase decomposition of complex sulfides are as follows: ΔH = 27.4 kJ/mol at 1643 K for MnTb4S7 and ΔH = 16 kJ/mol at 1574 K for MnTb2S4. The solubility of MnS in γ-Tb2S3 at 1650 K is 16 mol.%, and 5 mol.% of MnS is dissolved in α-Tb2S3 at 1170 K. The solubility of Tb2S3 in α-MnS-based solid solution (SS) is 6 mol.% at 1650 K and 3 mol.% of Tb2S3 at 1170 K. The temperature of the γ-Tb2S3 solid solution eutectoid decomposition is equal to 1350 K, and the composition of the eutectoid is 87 mol.% of Tb2S3. The coordinates of the eutectic between MnS-based solid solution and γ-Tb2S3-based solid solution is assumed to be equal to 27 mol.% of Tb2S3 and 1666 K. Calculations of the liquidus line, carried out using the Van Laar's equation, are in agreement with the experimental data. The Gibbs excess partial energies are calculated for the MnS–Tb2S3 system, and their negative values are correlated with the formation of two complex sulfides MnTb2S4 and MnTb4S7 in the system.

Based on the method of extended boundary conditions, an algorithm for the numerical solution of the two-dimensional problem of diffraction by a dielectric cylinder with wave number depending on the radial coordinate, which is partially covered by a perfectly reflective screen. The method is tested for the case of a homogeneous medium inside a dielectric cylinder. The accuracy of the fulfillment of the optical theorem is checked for various dependences of the wave number on the radial coordinate and the angular dependences of the scattering diagram are plotted for different opening angles of the reflective screen.

Practically all technological processes of metal products manufacturing by plastic deformation methods are associated with the formation of a self-balanced system of residual stresses in finished products. Level of residual stresses is in many cases an important parameter that determines the quality of products obtained as a result of plastic deformation. Reasons for the formation of residual stresses are diverse (inhomogeneity of plastic deformation, temperature field, phase transformations, etc.), which in their magnitude can exceed stresses from external loads. Currently, additional requirements are imposed on metal products in order to create machines and structures operating under high loads and speeds, sharp fluctuations in the parameters of the external environment. The experience of operating structures in various fields of technology and the results of numerous experiments show that residual stresses significantly affect the reliability and durability of machines and mechanisms. Based on the A.A. Ilyushin theory of unloading, analytical dependences were obtained for calculating the diagram of the change in residual stresses across the sheet thickness during bending under the rollers of leveler, as well as the springing angle. Formation of a diagram of residual stresses along the sheet thickness during leveling for the second, third and subsequent rollers of the leveler is considered. It was found that as a result of the superposition principle, the residual stresses diagrams under the second and third rollers are added, forming a total diagram after the second and third rollers. For the fourth, fifth, sixth and subsequent leveler rollers, an algebraic addition of the residual stress diagrams also occurs. It is shown that for a 45 steel sheet with a thickness of 10 mm, a width of 500 mm, r/h = 200, the maximum tensile residual stresses of 200 MPa are observed at a distance of Z/h = 0.3 from the neutral line along the sheet thickness. And in this case the discrepancy between the experimental and calculated values of residual stresses is 10 – 26 %, which makes it possible to recommend a method for calculating the residual stresses when leveling a sheet on a roller leveler for estimation of its quality.

Spatial (three-dimensional - 3D) computer model of the T-x-y diagram of the Ag - Cu - Ni system, which is promising for the development of environmentally friendly solders, is presented. The model is constructed on the basis of published data on the binary systems forming this ternary system, the concentration projection of the liquidus surfaces, and four isothermal sections. It is shown that the phase diagram (PD) consists of 14 surfaces and 9 phase regions. The adequacy of the model is confirmed by comparing the isothermal sections and the liquidus projection.

We report a near-broken-gap alignment between p-type FeWO4 and n-type Fe2WO6, a model pair for the realization of Ohmic direct junction thermoelectrics. Both undoped materials have a large Seebeck coefficient and high electrical conductivity at elevated temperatures, due to inherent electronic defects. A band-alignment diagram is proposed based on X-ray photoelectron and ultraviolet–visible light reflectance spectroscopy. Experimentally acquired nonrectifying I–V characteristics and the constructed band-alignment diagram support the proposed formation of a near-broken-gap junction. We have additionally performed computational modeling based on density functional theory (DFT) on bulk models of the individual compounds to rationalize the experimental band-alignment diagram and to provide deeper insight into the relevant band characteristics. The DFT calculations confirm an Fe-3d character of the involved band edges, which we suggest is a decisive feature for the unusual band overlap.

A new approach for estimating the structural parameters of asymmetric porous skin layer membranes fabricated by Loeb-Sourirajan method, to overcome the limitation of the models which are in existence is focused. Agreement between the calculated and the experimental data was then examined for all models to show the superiority of the newly proposed model. In particular, the new model could resolve the imperfections of the presently available models possessing the following superiorities: (i) scanning the entire range of permeance versus pressure diagram, (ii) no limit due to the conditions of data collection, and (iii) in contrast to the presently available models, the proposed model is capable to obtain the surface porosity (e) and the skin thickness (lp) separately. Interestingly, a high correlation was observed between the results of the wet/dry flow test and the proposed approach. The proposed model also makes it possible to correlate the structural parameters of the membrane with the condition of membrane fabrication.

This letter proposed a combined susceptibility diagram, applicable to investigating and differentiating the inherent mechanism of multipactor in dielectric-loaded microwave devices. This susceptibility diagram consists of average secondary emission yield on the dielectric surface and both the surfaces. Using this diagram, we predict the electron multiplication mechanism in the partially dielectric-loaded parallel-plate waveguide. It is found that the multipactor extinguishing only occurs for a low multipaction rate, while the saturation occurs for a higher multipaction rate. To verify its validity, the dynamic evolution of multipactor is investigated by electrostatic particle-in-cell. A good agreement between simulations and prediction results has been achieved. This susceptibility diagram thus constructed can provide a guidance to clearly identify the condition for multipactor extinguishing or saturation.

Punch–die misalignment is one of the factors that can contribute to drawn cup defects such as thinning and tearing. Deep drawing is a closed-die process, and defects can be identified only after the drawing is finished. In this work, the effect of punch–die misalignment severity on the drawing force and wall thickness distribution of electrolytic zinc-coated steel blank (SECC) was investigated. The stress–strain diagram and forming limit diagram of SECC material was determined and simulated using the Hill’48 model. Two conditions of punch–die misalignment were studied: single-axis and multi-axis misalignment. A high punch–die misalignment severity contributes to the increment in the drawing force. Furthermore, wall thickness distribution becomes non-uniform, and the thinning pattern increases due to the greater misalignment severity. For validation, an experiment was conducted on a universal tensile machine.

Wrinkling, which is primarily caused by insufficient blank holder force, is a significant issue that induces inconsistencies in forming parts, particularly in the deep drawing process. In this article, an investigation of the wrinkling in the deep drawing process of two-layer sheets is performed through an analytical approach, numerical method, and experimental tests. Increasing in the blank holder force, the process is under control by the proposed algorithm. Consequently, it aims to find the minimum required blank holder force to avoid wrinkling. The energy technique is utilized to predict the wrinkling in the analytical approach. Similarly, finite element simulations are implemented to investigate the effect of forming parameters on wrinkling. The experimental tests are performed to verify the analytical and numerical results. The impact of the material properties and stacking sequences (lay-up) on blank holder force and forming force are studied. Results show that the optimum blank holder force is dependent on the material properties, blank geometry, and layer stacking sequences. Also, a good agreement between analytical, numerical, and experimental results is achieved.

In this work, austenite–martensite transformation in a low alloy steel is modeled using Voronoi algorithm. The evolved fraction of martensite is predicted from the geometry of the Voronoi diagram constructed, incorporating nucleation kinetics of martensite and Voronoi algorithm. The obtained results are validated against the Koistinen–Marburger equation. The geometrical properties of evolved martensite phase are identified using the characteristics of Poisson–Voronoi diagram. Finally, the microstructure developed is used to analyze local stress–strain behavior of different phases in the microscale. Results show that higher stress values are distributed in martensite phase and higher strain values are distributed in austenite phase.

A plane-displacement diagram showing the four twinning elements, planes and directions, is fundamental to the classical theory of twinning. One aspect of the classical theory of type I and II twinning is shown to be inapplicable when the twin rotation is large. We employ the topological model with certain nonlinear characteristics to deduce a modified set of twinning elements. For twinning associated with a small rotation, both the classical theory and the topological model for type I and II twinning are shown, which give the same set of twinning elements. However, only the topological model is applicable for the large rotation case. As for the classical model, the twin plane in the type II twinning case is irrational unless it, and the type I twin is compound. Often, this irrational plane is close to a low-index orientation for a given orientation relationship. Then it can be favorable for the interface to break up into low-index, rational facets, separated by disconnections. This occurs without changing the orientation relationship. We apply the topological model to describe both the irrational type II twins and faceting in NiTi. The results agree with TEM observations.

The method of differential scanning calorimetry at various heating rates is used to measure the heat effect of the curing reaction of a EHD–MD grade chlorine-containing epoxy binder. Based on the experimental data, the kinetic parameters of the curing process are identified by the model-independent Friedman method. For the first time, an isoconversion thermokinetic diagram of the curing of a chlorine-containing epoxy binder is constructed and its glass transition temperature in the uncured state is determined, which makes it possible to evaluate the dependence of the latter on the degree of curing.

Water + elastin-like polypeptides (ELPs) exhibit a transition temperature below which the chains transform from collapsed to expanded states, reminiscent of the cold denaturation of proteins. This conformational change coincides with liquid-liquid phase separation. A statistical-thermodynamics theory is used to model the fluid-phase behavior of ELPs in aqueous solution and to extrapolate the behavior at ambient conditions over a range of pressures. At low pressures, closed-loop liquid-liquid equilibrium phase behavior is found, which is consistent with that of other hydrogen-bonding solvent + polymer mixtures. At pressures evocative of deep-sea conditions, liquid-liquid immiscibility bounded by two lower critical solution temperatures (LCSTs) is predicted. As pressure is increased further, the system exhibits two separate regions of closed-loop of liquid-liquid equilibrium (LLE). The observation of bimodal LCSTs and two re-entrant LLE regions herald a new type of binary global phase diagram: Type XII. At high-ELP concentrations the predicted phase diagram resembles a protein pressure denaturation diagram; possible "molten-globule"-like states are observed at low concentration.

Most technological processes of metal products manufactured by plastic deformation methods are associated with the formation of a self-balanced system of residual stresses in finished products. In many cases, the level of residual stresses is an important parameter that determines the product quality obtained as a result of plastic deformation. Reasons for the formation of residual stresses are diverse (inhomogeneity of plastic deformation, temperature field, phase transformations, etc.), which in their magnitude can exceed stresses from external loads. Currently, additional requirements are imposed on metal products in order to create machines and structures operating under high loads and speeds, sharp fluctuations in the parameters of the external environment. The experience of operating structures in various fields of technology and the results of numerous experiments show that residual stresses significantly affect the reliability and durability of machines and mechanisms. Based on the A.A. Ilyushin theory of unloading, analytical dependences were obtained for calculating the diagram of the change in residual stresses across the sheet thickness during bending under the rollers of leveler, as well as the springing angle. The diagram formation of residual stresses along the sheet thickness during leveling for the second, third and subsequent rollers of the leveler is considered. As a result of the superposition principle, it was found that the residual stress diagrams under the second and third rollers are added, forming a total diagram after the second and third rollers. For the fourth, fifth, sixth and subsequent leveler rollers, an algebraic addition of the residual stress diagrams also occurs. It is shown that for a 45 steel sheet with a thickness of 10 mm, a width of 500 mm, r/h = 200, the maximum residual tensile stress of 200 MPa is observed at a distance of Z/h = 0.3 from the neutral line along the sheet thickness. And in this case, the discrepancy between the experimental and calculated values of residual stresses is 10 –26 %, which makes it possible to recommend a method for calculating the residual stresses when leveling a sheet on a roller leveler for estimation of its quality.

The article is a continuation of the article ,DILATOMETRIC ANALYSIS OF COOLING CURVES FOR HIGH STRENGTH STEEL X153CrMoV12”, which deals with the phase transformations of tool steel X153CrMoV12. The experimental data obtained was used to evaluate the resulting CCT diagram, which consists of seven dilation curves. All experimental samples from dilatometric analyses were then subjected to microstructural analysis and hardness measurements to characterize the microstructure and hardness for each heat treatment mode tested. AFM microscopy was also used to study the carbides present in steels and their size and shape for all selected cooling modes.

The computational modelling of discotic molecules is a central topic in colloid science that is key for the smart design of a broad range of modern functional materials. This work lays out a versatile interaction model capable of exposing the rich mesogenic behaviour of discotics. A single coarse-grained spheroplatelet core framework is employed to generate a variety of pair interaction anisotropy classes, favouring specific relative orientations of the particles (stacked, side-side, crossed, T-shaped). This paves the way for the systematic tailoring of the discotic liquid phase diagram. Monte Carlo simulations are performed for an ensemble of case studies to illustrate the correlation between the topology of the interaction and the formation of stable nematic, smectic and columnar phases, as well as of less common cubatic, uniaxial and biaxial columnar domains.

It is still little or no knowledge about the properties of layered wood-based composites and nonwood components in the viscoelastic and plastic region of the force-deflection diagram (FDD). The properties of composites in this area are influenced by several factors such as the composition of the layered composite, the method of modification of the individual layers, the type of adhesive used, etc. This paper focuses on the analysis of the effect of the thickness of individual layers (5 and 9 mm) of beech wood (Fagus sylvatica L.), modification of these layers with different degrees of densification (10, 20, 30, and 40%) and the type of the nonwood component (carbon and high-strength glass fibers) used to reinforce the layered composite on the properties of materials in the plastic region of the FDD. The paper describes the impact of selected factors and those interactions behavior of the tangent modulus in the whole FDD. This is the first study that describes the development of layered wood-based composites and nonwood components in the viscoelastic and plastic region and analyzes the impact of most imported types of modifications on the characteristics in the viscoelastic and plastic regions.

The aim of the paper is to investigate the influence of compressive residual stresses on the fatigue initiation life (S-Nini) curve of AISI 1141 steel. The analysis has been performed by means of a micro-structurally-based fatigue crack initiation modelling approach. The focus is set on the local (surface) residual stresses typically imposed by a surface treatment technique known as shot -peening. By superimposing such stresses on stresses resulting from outer cyclic loading, it could be shown that an impact on the fatigue curve in the S-Nini diagram can be achieved.

The SnSe–Sb2Se3–Se system was studied by the emf method and X-ray powder diffraction analysis, and the diagram of solid-phase equilibria at 400 K was constructed. The partial thermodynamic functions of SnSe in various phase regions of the studied system were calculated from the measured emf of concentration cells with respect to a SnSe electrode in the temperature range 300–450 K. These data together with the corresponding thermodynamic functions of SnSe and Sb2Se3 were used to calculate the partial molar functions of tin in alloys, and also the standard thermodynamic functions of formation and standard entropies of the compounds SnSe2, Sn2Sb6Se11, SnSb2Se4, and Sn2Sb2Se5.

Crystal structure prediction (CSP) aims to determine the experimentally isolable crystal structure(s) of a molecule given only its 2D molecular diagram. The ability to match candidate structures to known experimental structures is critical in benchmarking CSP methods. In this work, a new approach to improve comparison of crystal structures using their calculated powder X-ray diffractograms (PXRD) is presented. The protocol involves anisotropic volume correction of the compared structure to that of the target. Its ability to distinguish matching structures from other candidates is assessed using the submissions to the 6th CSP blind test. The anisotropic volume correction is found to surpass currently available methods of PXRD comparison in its ability to separate similar from dissimilar structures. This is demonstrated by its ability to distinguish a polytype from a target structure, and by the identification of two uncredited matching structures in the 6th CSP blind test. The developed method yields a quantitative measure that is as useful as the root-mean-square deviation (RMSD) in atomic positions for structure comparison.

Origami-inspired multistable structures are gaining increasing interest because of their potential applications in fields ranging from deployable structures to reconfigurable microelectronics. The multistability of such structures is critical for their applications but is challenging to manipulate due to the highly nonlinear deformations and complex configurations of the structures. Here, a comprehensive experimental and computational study is reported to tailor the multistable states of origami-inspired, buckled ferromagnetic structures and their reconfiguration paths. Using ribbon structures as an example, a design phase diagram is constructed as a function of the crease number and compressive strain. As the crease number increases from 0 to 7, the number of distinct stable states first increases and then decreases. The multistability is also shown to be actively tuned by varying the strain from 0% to 40%. Furthermore, analyzing energy barriers for reconfiguration among the stable states reveals dynamic changes in reconfiguration paths with increasing strains. Guided by studies above, diverse examples are designed and demonstrated, from programmable structure arrays to a soft robot. These studies lay out the foundation for the rational design of functional, multistable structures.

Polycrystalline materials have been used throughout the recorded history, and their macroscopic properties strongly depend on the defects in their crystalline structures. Unique properties of the grain boundaries (GBs) should result from nearby nano-scale space, leading to the questions regarding the type of atomic polyhedra that pack the GB region as well as the universal set of structural units. It is essential to reveal the underlying mathematical framework for the polyhedral arrangement of GB structures and identify the origin of structure-property relationships in polycrystalline materials, which is a fundamental aspect but important for designing high-performance materials. Herein, 3D atomic structures of [001], [110], and [111] symmetrical tilt GBs are analyzed in the face-centered cubic (fcc) crystals, where the polyhedral units are rigorously defined in contrast to the polygonal arrangement within the 2D structural unit model. It is concluded that the GB region can only be packed by the bulk or GB-type polyhedral units with minor variations. In this study, the 3D arrangement of atomic polyhedra around the GBs is quantitatively determined and systematically described by numerical analysis. Moreover, the GB hierarchy directly follows the distribution of rational numbers that is represented by the modified Farey diagram, which represents the 3D atomic structure of the symmetrical tilt GBs in an fcc crystal. The definition of singular GB is proposed as the GB packed by at the most two types of polyhedral units, and any GB can be packed by the polyhedral units that form the singular GBs.

The three-dimensional computer model of the Co-Cu-CoS-Cu2S subsystem T-x-y diagram at temperatures above 800oC is represented. It is shown that the liquid immiscibility in the binary subsystem Cu-Cu2S is transformed within the ternary system with Co into the wide two-phase region of two immiscible melts, which interrupts the univariant curve of the Co and Cu2S co-crystallization. The special features of the structure of the solidus surface of cobalt, caused by liquid-phase immiscibility are considered.