Machines. Technologies. Materials.
Vol. 17 (2023), Issue 6

Table of Contents

  • MACHINES

    • Methods of Identifying Air Leaks in Pneumatically Operated Equipment in the Industry

      pg(s) 207-211

      In recent decades, it has become commonplace to automate assembly operations, often linked to production technologies within a single flexible production and assembly system. Assembly has a significant impact on global production, both in terms of its share of the total production cost of assembled products and in terms of the number of people employed in this area. The challenge for scientific and technical intelligence is to rapidly acquire production and assembly know-how to achieve target parameters in the shortest possible time. The use of all machinery and equipment forces people to think about how to use energy in the most efficient way, with the least possible loss, either in terms of money or in terms of energy. Every year the cost of energy increases, whether due to depletion of supplies or climate changes.
      Compressed air leaks are a serious problem in many industrial and manufacturing environments. These leaks not only increase operating costs but can also have a negative impact on the environment and the health of workers. Compressed air is the most expensive medium and when all basic costs are included, compressed air is many times more expensive than the equivalent of electricity. Therefore, it is necessary to analyse how to prevent high losses in the industry.

  • TECHNOLOGIES

    • The influence of electric discharge and solutions of surfactants on the filtration characteristics of porous, liquid-saturated media

      pg(s) 212-215

      The results of studies of the behavior of rocks with fluids under impulse pressure, which is induced by an electric discharge in solutions of surface-active substances (surfactants), are given. The mechanism of influence of high-voltage electric discharges and mechanical waves induced by them on the behavior of combined objects (porous rocks, hydrocarbon fluids filling their pores – oil and hydrogen surfactant solution, solid mineral sediment) is revealed.
      It was found out that the use of a water-oil emulsion as a working medium for high-voltage electric discharge significantly (2 times for sandstones and 1.5 times for carbonates) increases the efficiency of the electric discharge effect compared to water.
      The complex action of the electric discharge and the aqueous 0.3% solution of NMK-21, used as a working medium, leads to a synergistic effect in increasing the permeability of rocks by twice the sum of the effects for each component.
      Work results can be used in the development of scientific foundations of managing the filtration properties of porous materials of various origins.

    • Manufacturing Principals of Metal processing Lasers

      pg(s) 216-218

      This paper provides a concise overview of the manufacturing principles of metal processing lasers. Metal processing lasers are advanced tools used in various manufacturing industries for cutting, welding, and shaping metal materials. The presented highlights include the fundamental principles governing laser-based metal processing techniques, including laser beam generation, focusing, and interaction with metal surfaces. It also emphasizes the importance of precise control parameters, such as power, pulse duration, and wavelength, to achieve optimal processing results. Understanding these principles is crucial for enhancing productivity, quality, and efficiency in metal manufacturing processes.

    • Determination of the quality of welded joints after repairs of hot water pipes

      pg(s) 219-223

      The paper presents the results of an investigation aimed at analysing the current state of the art in the construction of hot water piping systems. Weld joint analysis and evaluation is an essential part of the inspection of hot water pipelines to ensure their safe operation. The practical part of this work is focused on the analysis and evaluation of the weld joint of original and new hot water piping. Destructive and non-destructive weld joint testing methods were applied to carry out the evaluation and analysis, the results of which were used to compare the welded joints on the hot water pipeline

    • Effect of production technique on a high silicon al-si-ni sintered alloy structure and properties

      pg(s) 224-227

      An experimental study was carried out to develop a technique for manufacturing a high silicon Al-Si-Ni sintered alloy with a coefficient of thermal expansion close to steels. A stage of hot forging was added to overcome porosity and improve silicon inclusions morphology to obtain better mechanical properties. Liquid and solid phase regimes of sintering were studied for the material made of the elemental components powders mixture as well as of a pre-alloyed powder. The impracticality of liquid-phase sintering modes is shown for this type of material primarily because of the tendency to liquid-phase exudation. It was proposed to carry out a solid-state vacuum sintering with subsequent hot deformation. Only the pre-alloyed powder is suitable for the technique; the other way, it leads to the course and sometimes, not equilibrium intermetallic inclusions will form in place of nickel particles because of the insolubility of Ni in solid Al. It is shown the possibility of successful plastic deformation of this material after sintering despite its extremely low ductility, which helps successfully overcome porosity and improve the characteristics of the microstructure of the material.

    • Development of Software Application in the Evaluation of Erythrocyte Aggregation Studied with Microfluidic Device

      pg(s) 228-231

      The main focus of this research is on the elaboration of the combined experimental approach and image analysis (based on the specialized software environments) to the research of erythrocyte aggregation, which is evaluated by the microfluidic device BioFlux. To realize a precise evaluation of the erythrocyte aggregation index based on the obtained, during the experiment images, are applied image processing toolbox from ImageJ and an elaborated computer program in IntelliJ IDEA (integrated development environment) as well. The obtained results for the index of erythrocyte aggregation, based on the developed methodology, show a statistically significant difference between the two studied groups with preeclampsia and healthy pregnant women.

  • MATERIALS

    • Polymer blends based on regenerated thermoplastics with low flammability

      pg(s) 232-235

      Composite materials based on regenerated thermoplastics of the polyolefin class with high parameters of stress-strain characteristics, which are highly resistant to open flame and combustion, have been developed. A synergistic effect was achieved by introducing a complex of modifiers into the matrix polymer, including regenerated particles of polytetrafluoroethylene, positioned as ultrafine particles (UPTFE), and residual products of the production of phosphate fertilizers – phosphogypsum (PG). The developed composite materials, processed by injection molding, make it possible to manufacture elements of metal-polymer rollers of belt conveyors used in the mining industry.

    • Size distribution of the shape memory alloys powders obtained by pulsed electrical discharge in cryogenic liquids

      pg(s) 236-239

      The relatively simple in implementation the pulsed electrical discharge method as an alternative to the gas atomization was performed for the production of powders of shape memory alloys such as Ti-Ni-based, Ni-Al, Cu-Al-Ni, Ni-Mn-Ga as well as the glass-forming alloy Zr-Ni-Cu-Ti-Al and pure Ti. Several methods have used to analyze the powder size distribution spanning from ordinary sieving and laser diffraction to SEM studying. The most effective SEM method gave the information both for powder sizes distribution and morphology of submicron and micron sized particles. The analysis of SEM images has shown that there are several peculiarities both in the powder size distributions and cumulative distributions. That features reflect the action of several mechanisms of the powder particles formation sized between several micrometers to hundred micrometers. In particularly the powders particles size is in average more in powders obtained in liquid nitrogen than in liquid argon independent on the materials of powder. As well that the number of hollows particles sized between 10 and 50 μm is much more in powders obtained in liquid nitrogen.

    • Titanium-Based Porous Structures Produced by Powder Metallurgy Approach

      pg(s) 240-243

      Porous materials are very efficient in absorbing mechanical energy, for instance, in combined armor, in order to improve the anti-ballistic protection characteristics. In the present study, porous titanium-based structures were manufactured via powder metallurgy methods using titanium hydride (TiH2) powder, which provided activated sintering, owing to dehydrogenation. The emission of hydrogen and shrinkage of powder particles on dehydrogenation also added a potential to control the sintering process and create desirable porosities. TiH2 powder was sintered with additions of ammonium as pore holding removable agents. The microstructures and porosities of sintered dehydrogenated titanium with different concentration ammonium were comparatively studied. Mechanical characteristics were evaluated using compression testing with strain rates varying from quasi-static to high levels. All testing methods were aimed at characterizing the energy-absorbing ability of the obtained porous structures. The desired strength, plasticity and energy-absorbing characteristics of porous titanium based structures were assessed, and the possibilities of their application were also discussed.