Machines. Technologies. Materials.
Vol. 19 (2025), Issue 7

Table of Contents

  • MACHINES

    • Wine microfiltration (MF) and water ultrafiltration (UF) flat sheet industrial membrane unit

      pg(s) 235-237

      They are designed for microfiltration membrane installations for wine (turbidity of the filter FTU 0.12-0.32) of the flat-parallel type with a filtration area of 10 m2, pore size of the membrane 0.1μm, 0.45μm, with a capacity of 250 l/h and for ultrafiltration membrane installations for water (turbidity of the filter FTU 0.02-0.05) with a capacity of 500 l/h. The wine microfiltration membrane installation ensures 100% removal of microorganisms and yeast, which results in ecologically clean, crystal clear, sterile, stable, high-quality wine. Installation of ultrafiltration membrane water purification completely removes suspended particles, colloids, bacteria, microorganisms, viruses, proteins, large organic compounds, microbiological residues and partially chemical components, including hardness salts, from water. Sterile drinking water (bottled water) is produced. Microfiltration and ultrafiltration membrane installations can be used by companies for the production of wine and drinking water, such as “family wineries” and “chateau”-type enterprises. Micro- and ultrafiltration membranes and equipment have a low cost, which significantly reduces the costs of wine and drinking water production.

  • TECHNOLOGIES

    • Use of hollow spheres to create double-layer filter materials

      pg(s) 238-240

      The results of comparative studies of the structure and properties of two-layer filter materials based on finely dispersed nickel powder are presented, in which the substrates were formed using hollow spheres and carbamide as pore-forming agents. The properties of the layers forming the structures of these two-layer materials, as well as the composite biporous material properties consisting of a mixture of hollow spheres of finely dispersed nickel powder and finely dispersed nickel powder are studied. The prospects for using hollow spheres to create two-layer filter materials are shown.

    • Determination of electrical energy consumption of welding cylindrical workpieces from alloy AA6060-T66 with TIG method

      pg(s) 241-243

      The paper presents an informational measurement system for measuring electricity consumption from a three-phase grid during welding of AA6060-T66 aluminium alloy cylindrical workpieces using the TIG (Tungsten Inert Gas) method. In addition to electricity consumption, the developed system can also monitor other related electrical quantities that give an image of the load that the consumer exerts on the grid. The importance of knowing these quantities is reflected in the fact that it can provide us with information about the energy efficiency of the method, as well as the possibility to determine the economic benefits of the chosen process and technology with the knowledge of the welding input parameters. These electricity consumption values affect the sustainability and have an impact on the environment. Energy input also directly affects the quality of the welded joint, which is reflected in penetration, formed microstructure and mechanical properties. Also, knowing this information opens up opportunities to compare performance with other methods. The paper presents the development of such a system, which includes the necessary hardware components, communication and software through which data acquisition is performed.

    • Research of a new technology for recycling obsolete metal products

      pg(s) 244-247

      This work is devoted to the study of a new technology for processing bar scrap – a precision shaft made of Cf53 structural steel (DIN 17212) that has proven its service life and produces high-quality finished metal products in the form of a screw reinforcement profile. The precision shaft used for recycling of its proven service life included two stages: preliminary deformation of the shaft on a radial shear rolling mill to obtain rods of the required diameter and create initial conditions for the formation of a gradient ultrafine-grained structure in the resulting screw profile; direct production of a screw profile with a gradient ultrafine-grained structure on a combined installation. The conducted research has shown that the new combined technological process of rolling bar scrap is feasible in practice and makes it possible to obtain a high-quality finished product from this scrap in the form of a screw reinforcement profile with a gradient ultrafine-grained structure.

    • Using surface microtexturing to enhance tribological properties of functional surfaces

      pg(s) 248-251

      The article presents the results of research aimed at applying selected optimal topography modification procedures to critical areas of shaped parts of molds in order to increase their service life. Molds for high-pressure casting of aluminum alloys were evaluated. The microgeometry of the sample surface was modified by low-energy laser radiation microtexturing. Lattice and stochastic textures were created by laser radiation. The integrity of the sample surfaces after the formation of ablation craters was checked by scanning electron microscopy. The dimensions of the random texture craters on which duplex PVD coating nACRo4. The tribological properties of surfaces with different microtextures were evaluated using the pin-on-ball method.

    • Using machine learning methods to predict processes and outcomes of high-voltage electrical discharge treatment of titanium powder in alcohol with implementation of volume-distributed multi-spark discharge

      pg(s) 252-256

      High-voltage electrical discharge (HVED) treatment of powder mixtures is a modern, efficient, and economically advantageous method for both particle size reduction and modification of the material’s phase composition. The primary mechanisms of particle destruction within the discharge zone include shock waves, microcavitation, ablation, collisions with chamber components, and mutual abrasion between particles.
      The application of machine learning methods to model HVED processes for titanium—a promising material for composite applications— enables more accurate predictions and optimization of the technological workflow.
      The data used for modeling were obtained between 2013 and 2021 and include results from the treatment of the initial titanium powder (with an average diameter of d₀ = 60 μm) in ethanol. This setup enabled the formation of a volume-distributed multi-spark discharge (VMD) within the ethanol–powder dispersed system. The dataset includes information on the number of treatment pulses, discharge gap, pressure in the discharge channels, pressure on the chamber walls, and the amount of titanium carbide formed during the treatment process.
      It was shown that the concentration of TiC gradually rises with the increase of specific treatment energy, regardless of the interelectrode gap. Specifically, at a specific energy (Ws) of 5 to 15 MJ/kg, the amount of titanium carbide reaches 10%; at 15 to 30 MJ/kg, it increases to 20%; and at energy levels above 30 MJ/kg, the TiC content reaches 30%.
      Keywords: Ethanol, Titanium, Titanium Carbide, High-Voltage Electrical Discharge, Volume-Distributed Multispark Discharge, Electric Discharge Dispersion, Plasma Technologies, Machine Learning, Logistic Regression, Random Forest

    • Advancing Carbon Capture, Utilization and Storage: Technological and Costs Pathways Towards 2050

      pg(s) 256-259

      Carbon capture, Utilization and Storage (CCUS) technologies are rapidly evolving as a critical component of global decarbonization strategies, particularly in hard-to-abate sectors such as natural gas processing, power generation, fertilizer, cement and steel production industries. Amine-based absorption systems are currently the most established capture method, widely applied in large point sources for natural gas processing and chemical industries. Alternatives such as membrane separation, adsorption, and direct air capture are also emerging, offering benefits for specific applications. CO2 transport is increasingly diversified, with supercritical CO₂ pipelines and liquefied CO₂ shipping offering scalable and flexible solutions. CO₂ storage is focused on deep saline aquifers and depleted oil and gas fields. Carbon capture costs are project-specific and depend on CO2 concentrations, facility size, and technology complexity, with costs ranging from 30 to 120 US$/tCO2. The CCUS chain will undergo substantial development in the next decades, both in technological maturity and economic viability. As of early 2025, the total global CCUS capacity was 50 million tonnes per annum (MTPA) and is expected to reach 1300 MTPA by 2050. Yet, this will cover only 6% of total global CO₂ emissions, far from any net-zero carbon emissions scenario. By 2050, modularization, improved materials, and process integration are expected to reduce investment costs by up to 30%.

  • MATERIALS

    • Effect of increased iron content on the porosity of AlSi7Mg alloy die castings

      pg(s) 260-263

      Defects in die castings can include underfilling, blistering, sticking to the mold, and cracking. However, the factor that most affects the quality of castings is porosity. The primary causes of porosity are gaseous impurities and improper mold venting, which lead to gaseous porosity. Additionally, a poorly selected gating system, low casting speed, excessively short piston paths, low post-pressure, and low casting temperatures all contribute to shrinkage porosity. An additional factor contributing to the occurrence of pores is the increasing proportion of scrap (from production and post-production), which contains a wide variety of impurities. Gaseous inclusions (e.g., hydrides) can be removed from the liquid alloy by refining it, but metallic impurities are worse. In Al-Si alloys, one of the most detrimental elements is iron, which enters solution due to its low solubility in the solid state, at levels exceeding 0.6 wt%. At high percentages, it crystallizes in morphologically unfavorable phases, which deteriorate service properties, increase brittleness and porosity of castings, and limit their use.
      This paper presents the results of a study of the effect of increased iron content (from 0.8wt.% to 1.5wt.%, in 0.2wt.% increments) on the porosity of AlSi7Mg alloy die castings. Porosity evaluation, conducted using microscopic metallography methods, was performed both qualitatively and quantitatively. It was found that the unfavorable morphology and dimensions of the Al5FeSi phase hinder the free flow of liquid alloy at the crystallization front. The lamellar-ligneous separations “close” the space between the dendrites of the α(Al) solid solution, causing the formation of shrinkage porosity. Increasing the iron content of die-cast Al-Si alloys forces the use of higher doping pressures, but not enough to cause “ejaculations” of the alloy in the dividing plane of the casting mold.

    • Densification and formation of structure and properties of inconel 625 alloy during direct powder forging

      pg(s) 264-267

      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.

    • Relationship between mechanical parameters of shear and tensile strength of polymer materials obtained by FDM extrusion of objects

      pg(s) 268-271

      This work examines the relationship between two of the most important mechanical parameters: shear and tensile strength in 3D printed polymer test specimens using Fused Deposition Modeling. Different types of materials were used, including those that are mechanically strong, easy to print, flexible, and heat-resistant, to determine their behavior. The study was conducted by testing test specimens printed with the same characteristics of percentage filling and pattern, layer height, and printing direction. The ratio between the shear strength and tensile strength of seven polymer materials with 30 % infill in percent was calculated. The values were compared with those of metals and polymers with 100 % density, and an estimate of the coefficient between the two parameters was made.