Machines. Technologies. Materials.
Vol. 20 (2026), Issue 4

Table of Contents

  • MACHINES

    • Tripod type parallel robots manipulators

      pg(s) 127-130

      Parallel robot manipulators (or parallel manipulators) feature closed kinematic chains. Compared to serial manipulators, they possess high load-carrying capacity, high positioning accuracy, and good dynamic characteristics. Most parallel manipulators with six degrees of freedom (DOF) utilize six legs and are commonly referred to as hexapods. This article focuses on the study of three-legged parallel manipulators, known as tripods. In comparison with hexapods, tripods offer larger workspaces and fewer singular configurations. The paper examines 3-PRRS and 3-PRPS tripods as examples, where P, R, and S denote prismatic, revolute, and spherical joints, respectively. Their structural synthesis was performed, their geometry investigated, and the inverse kinematics problem was solved.

    • Low-power induction motor for pumping system applications

      pg(s) 131-136

      Paper deals with a newly designed low-power three-phase induction electric motor for continuous duty cycle operation with application mainly in pumping system. The main features are presented. The problems and solutions related to the sizing and optimization of the motors during design according to different criteria and conditions are analyzed, with energy efficiency being the main determinant. Numerous graphical results obtained during the design are presented.

    • On the Geometric Role of the Distribution Parameter in Conic Spatial Rack Drives

      pg(s) 137-141

      This paper presents a study of some geometric characteristics of conic spatial rack drives with linear helicoids. Three variants of the conic configuration are considered — with convolute, involute, and Archimedean helicoids — and their action surface properties are analyzed in relation to the distribution parameter. The role of the distribution parameter in determining the geometry of the action surface and the position of each variant in the design parameter space is discussed.

  • TECHNOLOGIES

    • A Study of Hybrid Adhesive-Mechanical Joints Between Metals and Composites Formed Using Thermal Drilling Technology

      pg(s) 142-145

      This article presents a study of the possibility of creating adhesive-mechanical bonds between aluminum and a thermoplastic matrix composite. In detail, the influence of drilling process parameters on the shape of the bushing and the formation of joints with fiber-reinforced composites during direct drilling using various tool speeds and feeds is examined. Finally, the load-bearing capacity of the formed joints is presented.

    • Automatic quality control of blanked parts based on segmentation of shear and fracture zones using a convolutional neural network

      pg(s) 146-148

      A method for automatic quality control of blanked parts based on the ratio of the plastic deformation (shear) zone to the brittle fracture (rupture) zone on the cut surface is presented. Unlike known approaches that require strictly controlled shooting conditions, the proposed convolutional AI model (R-CNN) demonstrates robustness to a wide range of illumination: variations in brightness and light incidence angle reduce segmentation accuracy by no more than 3%. This is achieved through the use of local texture features that are invariant to brightness scale. The system takes into account the material grade — reference ratios of the zones are defined for each steel grade. Experiments were carried out on samples of three grades (AISI 1010, S235JR, AISI 1066). The classification accuracy of acceptable and defective parts was 98% relative to expert assessment.

    • Thermal and acoustic insulation studies of composite lime and lime-cement plasters based on foam glass granules and thermally treated rice husks

      pg(s) 149-151

      This paper presents the results of studies on the thermophysical and sound-insulating properties of new composite materials intended for interior and exterior plasters in construction. The materials were developed on the basis of foam glass granules and thermally treated rice husks using a specialized methodology. The guarded hot plate method was used to investigate the thermal insulation properties of the composite plasters. Tests for determining the acoustic insulation characteristics were carried out under laboratory conditions using the two-chamber method. The results show that the newly developed composite plasters exhibit better thermal and acoustic insulation properties than the standard plaster compositions traditionally used in construction.

    • New technology for producing a screw reinforcement profile from bar scrap of ferrous metals

      pg(s) 152-154

      This work is devoted to the development and research of a new technology for processing bar scrap from 40X steel to obtain high-quality finished metal products in the form of a screw reinforcement profile. The developed technology included two stages. At the first stage, the round-section bar scrap is formed on a radial-shear rolling mill to obtain conventional bars of the desired diameter and create initial conditions for the formation of an ultrafine grained gradient structure in the resulting screw profile. The second stage is the direct production of a screw profile with a gradient ultrafine-grained structure on a combined installation. Metallographic studies have shown that after the implementation of the second stage of obtaining a screw reinforcement profile, a gradient structure is observed in 40X steel, with equiaxed grains, the size of which lies within 1.2-1.4 μm in the peripheral region and to a greater extent with elongated, directional-oriented grains in the central region of the resulting reinforcement.

    • Monitoring the production process in production organization

      pg(s) 155-158

      The article deals with the assessment of the suitability of the manufacturing process and the analysis of the gear runout. The measurements were carried out using the 3D measuring device Wenzel WGT 280. The Palstat CAQ software was used to evaluate the process, while control charts for individual values and the sliding range were applied. The average value of the process reached 0.1460 and the sliding range was 0.00409. The suitability of the process was assessed using the Cp and Cpk indices with a required value ≥ 1.33, while the calculated values were 1.47 and 1.34. The results confirm that the monitored process is suitable. Subsequently, a comparison of the runout before and after heat treatment – nitriding was performed. The specified tolerance limits (0 μm to 0.0320 μm) were not exceeded, which confirmed the satisfactory state of the process even after the treatment.

    • Features of modeling complex twist deformation for obtaining multilayer metal cord structures

      pg(s) 159-161

      Features of modeling multilayer metal cord structures are shown. Data on the parameters of the numerical model of metal cord twisting and stretching are given. The dependences of the magnitude of stresses during the destruction of metal cord on the diameter of wires for various metal cord structures are determined. It is shown that symmetrical steel cord structures are less susceptible to a decrease in aggregate strength. The difference between the breaking forces of a multilayer symmetric metal cord with a core is about 10%. It is shown that with an increase in the wire diameter, there is no significant increase in the fracture stresses.

  • MATERIALS

    • Microstructural and Mechanical Performance of SiO₂-Reinforced Nickel-Based Nanocomposite Coatings

      pg(s) 162-166

      Nickel-based nanocomposite coatings reinforced with silicon dioxide (SiO₂) nanoparticles are attracting increasing interest in advanced marine applications due to their superior mechanical properties and resistance to surface wear. In this study, selective Ni-SiO₂ nanocomposite coatings were prepared and investigated to determine the relationship between microstructure, composition, and mechanical properties. The microstructure of the coatings was investigated using scanning electron microscopy (SEM). The analysis showed that the matrix is fine-grained and relatively homogeneous, containing well-dispersed SiO₂ nanoparticles at an amount corresponding to the optimal reinforcement level. Energy-dispersive X-ray spectroscopy (EDS) analysis confirmed that silicon oxide had been successfully incorporated into the nickel matrix and was uniformly distributed within it, and no significant signs of agglomeration were observed in the most effective compositions. Mechanical properties were evaluated by scratch tests to assess the coating’s adhesion and resistance to mechanical damage. The results showed that SiO₂-reinforced coatings exhibit significantly higher scratch resistance and higher critical load values. This improvement is attributed to dispersive strengthening, grain refinement, and the barrier effect created by hard ceramic nanoparticles, which together inhibit plastic deformation and crack propagation. In summary, the results of the study demonstrate the potential of Ni-SiO₂ nanocomposite coatings as durable protective solutions in marine environments, where resistance to mechanical wear and surface damage is particularly important. The study provides insights into how to adjust the microstructure and reinforcement distribution to improve the coating’s performance characteristics.

    • Experiment preparation with Phase Changing Materials for industrial application

      pg(s) 167-170

      This article summarizes the preliminary preparations for conducting experiments with phase change materials to determine their behavior during continuing heating and cooling processes. The goal is to summarize conclusions about the possibilities of using these materials in boilers and other water-heating tanks for industrial and domestic applications. The techniques, materials, and equipment that will be used are described, as well as the theoretical behavior of the materials that will be compared

    • Synthesis of polyphase materials containing pseudowollastonite

      pg(s) 171-173

      Based on waste biogenic calcium carbonate CaCO3 and silicon dioxide SiO2, polyphase materials with a predominant content of calcium silicate phases and a limited presence of silicon dioxide were synthesized in laboratory conditions. When preparing the experimental samples, solid-phase synthesis and thermal treatment modes with a maximum temperature of up to 1300oC were used. During the X-ray phase analysis of the obtained experimental samples, the presence of Ca3(SiO3)3 pseudowollastonite (dominant phase) was registered, β-Ca2SiO4 and SiO2 cristobalite. The main possibilities for further expedient modification of the used technological regimes are analyzed. The prospects for potential application of the synthesized phases for the preparation of various functional materials are considered. The study is consistent with modern trends in the use of technological approaches that allow the utilization of waste materials.

    • Increasing the Durability of Agricultural Working Bodies by Creating Nanostructured Coatings Using Plasma Jet Spraying

      pg(s) 174-176

      The article reveals a new method that relates to the treatment of active surfaces of agricultural working bodies, in particular harrow discs, by applying nanostructured coatings using atmospheric plasma jet spraying (APS). The process consists of preparing the surface by corundum blasting at a pressure of 5.5 bar, followed by preheating to 150°C and depositing a nanostructured powder of the WC-Co 88/12 type.
      The technical novelty lies in the synergetic optimization of the deposition parameters: current intensity of 550 A, hydrogen flow rate of 9 L/min, spraying distance of 100 mm and a high scanning speed of 500 mm/s, under forced post-deposition cooling.
      The technical result obtained by applying this process consists of creating a protective layer with porosity below 1.2%, adhesion of over 65 MPa and a hardness of 1150-1250 HV0.3, ensuring an increase in the durability of the working element of up to 2.8 times under conditions of severe abrasive wear.