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This paper describes how the method of preparing a composite TiC - n Ni mixture (n = 40, 50, 75% is the volume fraction of nickel) affects the carbide content in the coating material obtained by cold spraying. It is shown that, when coatings are obtained from a powder mixture prepared in a V-shaped mixer, the titanium carbide content is lower than in coatings obtained from powders mechanically processed in a high-energy planetary mill. In the case of mixing the powder mixture in a V-shaped mixer, fine titanium carbide particles do not reach the substrate surface during spraying because they are decelerated in a shock-compressed gas layer when a supersonic jet accumulates on an obstacle. Thus, these particles do not participate in the formation of the coating. Spraying a mechanically treated powder consisting of composite agglomerated TiC-Ni particles allows for a significant (approximately 1.8-fold) increase in the carbide content in the coating

The impact of vibrating manipulation on arterial hemodynamics and mechanical properties is explored by using the finite element method for the fluid-structure interaction. Numerical simulation results show that massage greatly changes the flow behavior of blood within the artery. Under the massage manipulation, the mean blood flow increases by more than 5.34% at a frequency of 2ʄ₀ and by smaller values at frequencies of f0 and 4ʄ₀. The blood flow has obvious disorder characteristics and an obvious wall shear stress concentration in the mixed flow area. The von Mises stress of the artery wall increases, reaching a peak value at the maximum deformation.

Predicted numerical distributions of the vibrational temperature of molecular oxygen behind a reflected shock wave are compared with experimental measurements in a shock tube. The computations are performed with the use of five two-temperature models (those developed by Park and Kuznetsov, β-model, and models of Marrone and Treanor and by Macheret and Fridman), five dissociation constants, and three variants of the source term that describes the rate of change of the vibrational energy due to chemical reactions. The Landau-Teller model is used to calculate the rate of translational-vibrational energy transfer, and the time of vibrational relaxation is calculated by the Millikan-White formula with allowance for Park's high-temperature correction. The numerical and experimental results are found to be in reasonable agreement. The greatest difference between the numerical and experimental data is observed in the region of relaxation of the shock wave incident onto the wall.

To study the effect of laser surface remelting (LSR) on the organization and properties of a 304 stainless steel surface layer, the microscopic morphology, hardness, roughness, adhesion, and corrosion resistance of the remelted layer (RL) are examined by changing the laser scanning speed (LSS). The experimental results show that the LSR technique hardens the 304 stainless steel substrate surface with a substrate hardness of 185 HV, and the maximum hardness after remelting is 248.9 HV. With an increase in the LSS, the surface roughness gradually decreases, while the bonding force first increases and then decreases, with the maximum bonding force being 26.1 N. At the LSS of 20 mm/s, the phase distribution in the RL is more uniform. The maximum self-corrosion potential of the RL reaches -0.718V, and the self-corrosion current density is 3.872 A/cm². The surface properties of 304 stainless steel are improved by using LSR.

This paper presents the results of numerical analysis of the filtration equations for highly miscible liquids obtained by two-scale homogenization of the Navier-Stokes and Cahn-Hilliard equations for two-dimensional flows. It is shown that the permeability tensor is generally anisotropic. For one-dimensional flows, the miscibility dynamics is investigated, and it is shown that the displacement of one phase by injection of another phase can occur even in the absence of a pressure gradient in the sample.

Taking into account the degradation of the properties of materials, an analysis of the nonlinear processes of deformation and fracture in a preloaded three-dimensional body with a sharp concentrator in the zone of a dissimilar joint under impact was performed. A generalized mathematical model of nonlinear interrelated deformation and destruction of damaged polycrystalline media subjected to time-varying thermomechanical influences is presented. The strong nonlinearity of the model is due to large (finite) strains and the strain-rate dependent behavior of media with a variable microstructure. Taking into account the anisotropic hardening of media and the Bauschinger effect, the corresponding nonlinear boundary value problems are formulated and their solutions are obtained using efficient numerical methods. The viscosity of the medium and second-order gradients from the internal variables of the system were used as regulators of the correctness of the problem statement. Experimental data were used to test the model. Simulation results presented.

The strength of a rectangular plate with two opening-mode (mode I) edge cracks was studied using the Neuber-Novozhilov approach and a modified Leonov-Panasyuk-Dugdale model with nonzero prefracture zone. A coupled discrete-integral fracture criterion is used since the stress field in the vicinity of the crack tip has a singularity. At the tip of a real crack, the fracture criterion for ultimate strain is satisfied, and at the tip of the model crack, the criterion for normal stresses is satisfied. The constitutive equations for the analytical model are analyzed. Simple formulas for fracture load in quasi-brittle and quasi-ductile fracture are derived. Plate fracture curves are constructed for a plane stressed state.

Equations are obtained that describe the process of propagation of elastic waves in a collapsing solid. It is shown that the solution of the equation for the velocity potential of acoustic emission longitudinal waves can be represented as a superposition of the fields of an ensemble of radiating cavities - monopoles. The parameters of the ensemble of monopoles are selected in such a way that the structural characteristics of a medium with cavities differ slightly from those of a solid body.

The microstructure, surface quality, and thermal shielding properties of the coatings prepared by the methods of magnetron sputtering and electroplating are studied. The results show that the Cr-Ag coating prepared by means of magnetron sputtering is smoother, its porosity and emissivity are lower, and the hardness is higher than that of the coating prepared by means of electroplating.

An algorithm for solving an inverse problem of shaping of a ribbed panel made of the AK4-1 alloy (analog of the AA2018 and Al-Cu₂-Mg₂-Ni₁ alloys) at a temperature of 200 °С is proposed. The problem is reduced to solving auxiliary direct problems on the stress-strain states of the elements of the panel structure. The structural elements are taken to be T-beams subjected to pure bending. The resultant moment for obtaining a desired shape is calculated by the Nelder-Mead optimization method. Two methods of obtaining target-shaped articles are considered: deformation under the plastic flow condition and under the creep condition. The material models used in the study take into account the difference in the mechanical properties under tension and compression, as well as the presence of accumulated damage in the material. The calculations are performed with allowance for elastic spring unloading of the article after load removal.