International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

New types of materials have been developed for years, including titanium-based alloys, which have the potential for various applications. Due to the combination of their very good mechanical properties with outstanding corrosion resistance and excellent biocompatibility, titanium alloys are developing into materials that can be used in aerospace, automotive, energy systems and especially in medicine. A fundamental understanding of the phase transformations that occur at high temperatures in all these cases, especially during cooling from elevated temperatures, is necessary to achieve optimal mechanical properties of titanium alloys. It is known that the mechanical properties of titanium alloys depend on a significant extent upon the microstructure. Therefore, it is very important to understand the nature of the phase transformations that occur under different heat treatment conditions the leads to microstructure development of titanium alloys microstructure. The aim of this article is to review the current state of knowledge and previous research and to point out some of the most interesting phase transformations of titanium alloys.

Aluminum alloys are critical in industries such as aerospace and automotive due to their lightweight, strength, and corrosion resistance. Optimizing their properties is challenging and benefits from advanced predictive tools. This paper explores the use of mathematical modeling in understanding and designing aluminum alloys. Techniques like thermodynamic modeling (e.g., CALPHAD), phase transformation kinetics, and mechanical property simulations are reviewed. Computational methods, including finite element analysis and machine learning, are highlighted for their roles in alloy design and manufacturing, such as casting and additive manufacturing. Comparisons between model predictions and experimental results demonstrate accuracy and limitations. Applications in optimizing material properties and improving manufacturing processes are discussed. By accelerating alloy development and enabling tailored properties, mathematical modeling emerges as a transformative tool, advancing aluminum alloy research and driving innovation across industries.

Shape memory effects have been observed not only in bulk materials but also in PVD thin films. We have deposited copper-base shape memory alloys (SMAs) on Al substrates using DC sputtering. The coatings exhibit diffusionless transformation from the hightemperature austenite phase to the low-temperature martensite phase. This can be both, thermally controlled as a kind of two-way memory effect and stress-induced, giving a pseudoelastic behavior. The structures and microstructures of the coatings were analyzed by X-ray diffraction and optical microscopy. The martensitic transformation temperature was determined by dilatometric measurement. The coatings exhibit a martensite start temperature (Ms) very close to that of bulk materials. The SMA thin films have the ability to recover from large transformation stresses and strains when heated. In addition, their pseudoelasticity makes them potentially suitable as a protective layer against cavitation erosion.

This study is concerned with the dynamical laws for particle velocities in supercooled and supersaturated liquids. The cases of spherical and ellipsoidal particle shapes are considered. Also, we consider various growth conditions such as stationary and non-stationary approximations, the shift of crystallization temperature caused by the phase interface curvature, and the kinetics of atoms sticking to the solid-liquid boundary. The dynamical laws under consideration are in good agreement with experiments.

It was found that in the process of pulsed laser action, various phase and structural transformations occur in non -metallic inclusions, which take place under nonequilibrium conditions. It is shown that the melting of inclusions under laser action is corresponded with change of their structure and phase composition. Also it is shown that the nature of these transformations depends on the type of nonmetallic inclusion. It was found that nonequilibrium phase transformations contribute to a change in the structure, phase composition, properties and sizes of nonmetallic inclusions, as well as the inclusion-matrix interphase boundaries of steel. It is shown that changes in the structure and properties of non-metallic inclusions affect their behavior and the formation of defects in the laser-strengthened layer of steel
products.

Methods for calculating the nonequilibrium phase transformations during the condensation of supercooled steam in the turbine flow path are developed. In the process of realization, the development of the classical Zel’dovich-Frenckel’s theory for the case of nonstationary nucleation of a new phase with fast extensions of supercooled steam is considered. A numerical-analytical method for calculating condensation was designed and implemented in the form of a software package, which consistently takes into account the nonstationarity of the process. Numerical studies have shown high efficiency and accuracy of the method.

The influence of various factors on the processes of nonequilibrium crystallization of dipeptide (DPT) from its aqueous solutions has been studied. The nonequilibrium crystallization leads to the formation of spatially heterogeneous structures. Depending on the charge of the DPT molecule (neutral or anion), not only the morphology of the surface of the layers changes, but also its electronic structure. The important role is played by the properties of the substrate-layer interfaces, which are responsible for the formation of ferroelectrics on gold during the crystallization of the DPT anion. The structure of the solid layers is also significantly affected by charges on the substrate surface, which can partially or completely compensate for the charges of individual functional groups in the PT molecule. The observed effects of bipolar resistive switching in peptide layers and the formation of ferroelectrics can find practical application as a smart material of memristor organic lectronics.

The effect of severe plastic deformation on the kinetics of second phases in a dispersion-strengthening Cu-Cr-Zr alloy is investigated. The observed set of phenomena indicates that during SPD processing there occurs a complex interaction between deformation mechanisms and the processes of dissolution and precipitation of second-phase particles in the copper matrix, influencing structure refinement and resulting in a change of the particle sizes and their distribution, and consequently, the material’s strength.