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

This study investigates the compaction and deformation behavior of Inconel 625 powder using direct powder forging at temperatures of 950 °C and 1150 °C. Finite element modeling was conducted and validated with experimental data. The residual porosity after deformation was 6.5% at 950 °C and 2% at 1150 °C. Samples forged at 1150 °C demonstrated superior mechanical properties, including a bending strength of 1750 MPa and fracture toughness of 42 MPa·m¹ᐟ². In contrast, lower temperature deformation resulted in poorer grain boundary quality and reduced mechanical performance. Post-deformation annealing at 950 °C enhanced microstructural integrity through recrystallization, improving strength to 1540 MPa and toughness to 30.9 MPa·m¹ᐟ². Flow stress at 700 °C ranged from 450 to 650 MPa, confirming the material’s suitability for high-temperature aerospace applications. The findings indicate that 1150 °C is the optimal forging temperature for producing dense, high-strength components from Inconel 625 powder.

This work was aimed to smelt high-entropy alloys (HEAs) based on inexpensive and common metallic elements using iron-based alloys, ligatures, commercially pure metals and study HEAs’ phase structure. High-entropy alloys of the FeNiCrCuAl system were smelted in air using induction furnace in a crucible with a rammed neutral lining made of aluminum and magnesium oxides. Elements of Fe, Ni, Cr, Cu, Al were added by way of high-alloyed cast iron or stainless-steel grade X10CrNiTi18-10 (EN 1.4541), low-carbon ferrochrome of industrial grade FeCr70C1, binary Cu-33Al ligature, tough-pitch copper and semi-finished nickel. The investigated alloys were prepared by lost foam and sand mold casting methods. A study of the microstructure showed the presence of rounded shape branches of dendrites, copper-rich interdendritic space and high-chromium carbides in the structure of samples. The phase composition of the as-cast FeNiCrCuAl alloys was represented by several phases: ordered solid solution with primitive cubic lattice of type B2, solid solutions with BCC and FCC lattices and complex carbides (FeCr)₇C₃.

A new approach for analyzing the content and structural units of modern lectures in a higher educational institution is presented. The requirements that should be presented to the lecture in order for it to meet its modern purpose in the continuous education of students have been analyzed. It is quite natural that individual lectures from certain disciplines may not meet all the listed requirements at the same time. However, any lecture should satisfy the educational, developmental and educational functions as much as possible.

Complex structural steel structure projects must be realized with the aid of specialized logistical technologies to meet all the design technical specifications. Selecting which equipment to employ, particularly when we need to elevate heavy structural steel components at an elevation higher than 8 meters, requires not only experience and the use of standard techniques for the logistic management of construction processes but also requires stress capacity calculations of the constituent elements of the machines that we will use for the implementation of the project. An indispensable machine for the realization of steel structures is the telescopic forklift, which serves to lift steel elements at different heights and positions, for a relatively long time, to assemble structure elements such as columns, trusses, beams, automated cranes, etc. In this paper, we have designed a telescopic forklift and calculated the stress capacity of the structural elements that compound the telescopic-boom, using the finite element software (FEM) Solid Works. Carrying out simulations with the corresponding load that we have to deal with in the realization of the project, allows us to change the section thickness of the telescopic boom or to use other logistic equipment with a higher capacity.

The possibility of improving the structure and properties of aluminum cast alloy based on Al-Si-Mg due to the melt treatment in the magnetohydrodynamic installation has been studied in this work. Also, the optimization of the chemical composition and select the optimal modes of heat treatment of the alloys to improve the structure and complex of properties was carried out. It was shown that the most effective alloying element which improve the strength characteristics of Al-Si-Mg alloy is lithium. It was found that the introduction of lithium into the alloy in the amount of 0.2% leads to the modification of the Al-Si eutectic and provides the increase in the yield strength and tensile strength by 15%, while the ductility increases more than three times as much as compared to that of the base alloy.

The phase and structure formation of aluminum-matrix composite materials reinforced with titanium carbide during their synthesis and consolidation using the forging were investigated. The influence of copper additives on the structure formation, density, porosity, and hardness of aluminum-matrix composites was determined. The research results revealed the presence of Al+Cu+TiC phases in copperalloyed samples. Studies of density and porosity showed that the samples without copper additives were maximally densified after hot stamping and had minimal porosity, unlike the copper-alloyed composites.

On the example of a powder based on mullite, the process of obtaining highly porous ceramic filter materials using porous shells on removable spherical carriers was tested, including the deposition of thin shell coatings from powder based on mullite on spherical granules of expanded polystyrene, pressing the mixture in the form of evenly distributed in the powder of the same composition ( matrix) and sintering. It’s shown that the resulting material is characterized by a good complex of filtering properties and a developed biporous structure.

Two-dimensional van der Waals (vdW) materials possess novel physical properties and promising applications. A wide range of 2D vdW materials having been obtained via the chemical vapor transport (CVT) method. In this work, we develop the controllable growth meyhod of 2H-NbSe2 single crystals via the CVT method. The quality of fabricated crystals was characterized by X-ray diffraction, and electron dispersive spectrometry (EDS) measurements. Crystals of the best quality were successfully grown under selected temperature/time schedule.

Two-dimensional van der Waals (vdW) materials possess novel physical properties and promising applications. A wide range of 2D vdW materials having been obtained via the chemical vapor transport (CVT) method. In this work, we develop the controllable growth meyhod of 2H-NbSe2 single crystals via the CVT method. The quality of fabricated crystals was characterized by X-ray diffraction, and electron dispersive spectrometry (EDS) measurements. Crystals of the best quality were successfully grown under selected temperature/time schedule.

The work shows that there is no significant change in the phase composition of composites with a change in the synthesis temperature, so we can use pre-synthesized heats at a temperature of 950 oC to obtain hot-stamped aluminum-based composites. The best characteristics of the synthesized titanium carbide were obtained for the composition 45Al-11C-44Ti (%, wt.). The lattice period of titanium carbide for this sample is 0.4324, and the particle size of titanium carbide formed after sintering is 0.8-1.5 μm. The influence of the component composition of the initial charge on the features of the structure and the phase composition of the thermally synthesized heat of the Al-C-Ti system was established.

The article presents the results of studies on the study of the physical and mechanical characteristics of polymeric materials modified with mechanically activated particles. It is shown that the use of mechanically activated nanosized particles makes it possible to achieve a significant effect of increasing operational characteristics at relatively low degrees of modification of 0.05% wt. – 3% wt. The use of modifiers at such concentrations in polymer matrices makes it possible to preserve the basic technology for the processing of polymeric materials and equipment in the manufacture of composite materials on a polymer matrix.

The object of the study was carbon particles obtained by the method of self-propagating high-temperature synthesis. The purpose of the work is the development of compositions and technologies for obtaining competitive composite materials modified with low-dimensional carbon modifiers based on vegetable raw materials.