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Wyszukujesz frazę "Lemishka, I.A." wg kryterium: Autor


Wyświetlanie 1-4 z 4
Tytuł:
Investigation of structural-geometric parameters and elemental composition of spherical VT20 alloy powders
Autorzy:
Duriagina, Z. A.
Filimonov, O. S.
Kulyk, V. V.
Lemishka, I. A.
Kuziola, R.
Powiązania:
https://bibliotekanauki.pl/articles/368582.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
spherical VT20 alloy powders
structural-geometric parameters
additive technologies
fluidity
bulk density
hydrodynamic radius
proszek sferyczny
technologie przyrostowe
płynność
gęstość objętościowa
promień hydrodynamiczny
Opis:
Purpose: Identification of structural-geometrical parameters, technological properties and elemental composition of spherical powders in a wide fraction range with respect to the VT20 alloy has been carried out. This is important for evaluating the optimum filling of a given volume by mixture of powders of different fractions during 3D printing. Design/methodology/approach: During the investigation of spherical Ti-alloy powders, a comprehensive approach was performed using Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Dynamic Light Scattering (DLS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The surface morphology of the powders was studied on a Tuescan Vega 3 Scanning Electron Microscope. Using the Quantax energy dispersive spectrometer, element distribution maps were obtained and histograms of element distribution in the investigated powders were constructed. ICP-MS analysis was performed to clarify the elemental composition. DLS analysis using Malvern's Zetasizer Nano-ZS equipment allowed us to determine the functional parameters (hydrodynamic radius – Rh, zeta potential – z and specific conductivity) of particles of titanium alloy powder that indirectly indicate a tendency to form conglomerates. Findings: According to the microscopic examinations, the VT20 alloy powder consists of globular-shaped particles with the lamellar traces on their surfaces. The uniformity of the chemical element distribution within each fraction of the investigated powders was confirmed by EDS, and the full conformity of the powder fractions with the elemental composition of the VT20 alloy was confirmed by ICP-MS. The DLS method allowed to establish that the formation of conglomerates would not occur within the studied fractions of the VT20 alloy powder. Research limitations/implications: The use of high sensitive investigation methods gives understanding of the mechanisms of fine structure formation and possibility to control the processes of powder coagulation in the stage of electrostatic interactions. Practical implications: The obtained results can be used for the formation of fine spherical particles of the powder, but at the same time, these technologies can be extended for the particles of non-spherical shape. Originality/value: The DLS method allowed to establish that the formation of conglomerates would not occur within the studied fractions of the VT20 alloy powder. This, in turn, will improve powder melting during 3D printing. The measured zeta potential values allowed us to reveal mechanisms of fine structure formation and to control the processes of powder coagulation in the stage of electrostatic interactions.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2019, 95, 2; 49-56
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of water vapor containing hydrogenous atmospheres on the micro-structure and tendency to brittle fracture of anode materials of YSZ–NiO(Ni) system
Autorzy:
Kulyk, V.V.
Vasyliv, B.D.
Duriagina, Z.A.
Kovbasiuk, T.M.
Lemishka, I.A.
Powiązania:
https://bibliotekanauki.pl/articles/2175787.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
YSZ–NiO ceramics
hydrogen
water vapor
ceramika YSZ-NiO
wodór
para wodna
Opis:
Purpose: The purpose of this work is to estimate the tendency to brittle fracture of the YSZ–NiO(Ni) anode cermet in a hydrogenous environment with various concentrations of water vapor. Design/methodology/approach: YSZ–NiO ceramic plates were fabricated by sintering in an argon atmosphere. The treatment of material was performed in a hydrogenous environment with various concentrations of water vapor. The strength test was performed under three-point bending at 20°C in air. The microstructure and morphology of the fracture surface of the specimens were studied using a scanning electron microscope (SEM) Carl Zeiss EVO-40XVP. The chemical composition was determined using an INCA ENERGY 350 spectrometer. Microhardness measurements were performed on a NOVOTEST TC-MKB1 microhardness tester. The configuration of the imprints and cracks formed was studied on an optical microscope Neophot-21. The porosity of the materials was investigated by analysing the SEM micrographs using the image processing technique. Findings: Peculiarities of changes in the microstructure, the morphology of specimens fracture surface, physical and mechanical characteristics of YSZ–NiO(Ni) material for solid oxide fuel cell (SOFC) anodes of different preconditioning modes aged under various partial pressures of water vapor in a hydrogenous environment are found. Research limitations/implications: To study the actual behaviour of the YSZ–NiO(Ni) anode material in the operating environment, it is necessary to evaluate its strength, Young’s modulus, microhardness, and fracture toughness by changing with a certain step the partial pressure of water vapor in the whole range noted in this work.Practical implications: Based on the developed approach to assessing the propensity to brittle fracture of the formed cermet microstructure, it is possible to obtain an anode material that will provide the necessary functional properties of a SOFC. Originality/value: An approach to estimating the propensity to brittle fracture of a formed cermet structure is proposed based on the microhardness and fracture toughness characteristics obtained by the Vickers indentation method.
Źródło:
Archives of Materials Science and Engineering; 2021, 108, 2; 49--67
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure and electrochemical properties of the vanadium alloys after low-temperature nitrogen plasma treatment
Autorzy:
Duriagina, Z. A.
Ryzhak, D. D.
Kulyk, V. V.
Tepla, T. L.
Lemishka, I. A.
Bohun, L. I .
Powiązania:
https://bibliotekanauki.pl/articles/1818517.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
vanadium alloy
surface layers
microhardness
corrosion
stop wanadu
warstwy powierzchniowe
mikrotwardość
korozja
Opis:
Purpose: The proposed research aims to determine the expediency of surface treatment of vanadium alloys of V-Cr and V-Ti systems due to irradiation of their surfaces with low- temperature nitrogen plasma using plasma torch NO-01. Design/methodology/approach: The investigation of microstructure and X-ray fluorescence analysis (XRF) of the samples were performed using an electron microscope TESCAN Vega3. The microhardness (Vickers hardness) of the samples was measured before and after surface treatment. The study of corrosive properties of the surface layers was performed by an electrochemical impedance spectroscopy (EIS) method. Corrosion damages were identified using impedance dependences. Findings: The microstructure of the surface layers of the V-8Ti, V-15Cr, and V-35Cr alloys in the initial state and after plasma treatment have been investigated. The chemical composition of the surface layers is determined and comparative measurements of the microhardness of these alloys are carried out. Corrosion-electrochemical properties (corrosion potentials, electrochemical impedance spectroscopy and constructed potential-dynamic polarization curves) of investigated alloys after treatment with nitrogen plasma are evaluated. Research limitations/implications: The results obtained using laboratory samples should be checked at the conditions of power equipment operation. Practical implications: This treatment has advantages over other methods of surface engineering since it provides strong surface plastic deformation and the possibility of formation of secondary phases resulting in increases in surface hardness and corrosion resistance. Originality/value: Vanadium alloys have significant advantages over other structural materials due to their high thermal conductivity and swelling resistance, high strength and plasticity up to temperatures of 700-800°C, and good weldability.
Źródło:
Archives of Materials Science and Engineering; 2020, 102, 1; 5--12
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The character of the structure formation of model alloys of the Fe-Cr-(Zr, Zr-B) system synthesized by powder metallurgy
Autorzy:
Duriagina, Z. A.
Romanyshyn, M. R.
Kulyk, V. V.
Kovbasiuk, T. M.
Trostianchyn, A. M.
Lemishka, I. A.
Powiązania:
https://bibliotekanauki.pl/articles/366907.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
model alloys
phase diagram
microstructure
microhardness
XRD analysis
stop modelowy
diagram fazowy
mikrostruktura
mikrotwardość
analiza XRD
Opis:
Purpose: The purpose of the work is to synthesize and investigate the character of structure formation, phase composition and properties of model alloys Fe75Cr25, Fe70Cr25Zr5, and Fe69Cr25Zr5B1. Design/methodology/approach: Model alloys are created using traditional powder metallurgy approaches. The sintering process was carried out in an electric arc furnace with a tungsten cathode in a purified argon atmosphere under a pressure of 6·104 Pa on a water cooled copper anode. Annealing of sintered alloys was carried out at a temperature of 800°C for 3 h in an electrocorundum tube. The XRD analysis was performed on diffractometers DRON-3.0M and DRON-4.0M. Microstructure study and phase identification were performed on a REMMA-102-02 scanning electron microscope. The microhardness was measured on a PMT-3M microhardness meter. Findings: When alloying a model alloy of the Fe-Cr system with zirconium in an amount of up to 5%, it is possible to obtain a microstructure of a composite type consisting of a mechanical mixture of a basic Fe2(Cr) solid solution, solid solutions based on Laves phases and dispersive precipitates of these phases of Fe2Zr and FeCrZr compositions. In alloys of such systems or in coatings formed based on such systems, an increase in hardness and wear resistance and creep resistance at a temperature about 800°C will be reached. Research limitations/implications: The obtained results were verified during laser doping with powder mixtures of appropriate composition on stainless steels of ferrite and ferrite-martensitic classes. Practical implications: The character of the structure formation of model alloys and the determined phase transformations in the Fe-Cr, Fe-Cr-Zr, and Fe-Cr-B-Zr systems can be used to improve the chemical composition of alloying plasters during the formation of ferrite and ferrite-martensitic stainless steel coatings. Originality/value: The model alloys were synthesized and their phase composition and microstructure were studied; also, their microhardness was measured. The influence of the chemical composition of the studied materials on the character of structure formation and their properties was analysed.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2020, 100, 2; 49-57
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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