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Wyszukujesz frazę "iron surface" wg kryterium: Temat


Tytuł:
Density Functional Theory Study Of The Interaction Of Hydroxyl Groups With Iron Surface
Badanie wzajemnego oddziaływania grup hydroksylowych na powierzchni żelaza za pomocą teorii funkcjonału gęstości
Autorzy:
Nunomura, N.
Sunada, S.
Powiązania:
https://bibliotekanauki.pl/articles/355298.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
density functional theory
hydroxyl groups
iron surface
adsorption energy
teoria funkcjonału gęstości
grupy hydroksylowe
powierzchnia żelaza
energia adsorpcji
Opis:
The electronic interaction of hydroxyl groups with Fe(100) surface is modelled using a density functional theory (DFT) approach. The adsorption energies and structures of possible adsorption sites are calculated. According to our calculations of the adsorption energies, the interaction between oxygen atom of OH species and surface iron atom is shown to be strong. It is likely to be due to the interaction of the lone-pair electrons of oxygen and the 3d orbital electrons of iron atom. At low coverage (0.25ML), the most favorable adsorption sites are found to be two-fold bridge sites, and the orientation of the O-H bond is tilted to the surface normal. Further, the adsorption energy is found to be decreasing with the increasing OH group coverage.
Wzajemne oddziaływanie elektronowe grup hydroksylowych na powierzchni Fe(100) modelowano stosując metodę teorii funkcjonału gęstości (ang. density functional theory; DFT). Dokonano obliczeń energii adsorpcji oraz struktury potencjalnych centrów adsorpcji. Na podstawie otrzymanych wyników stwierdzono, że pomiędzy atomem tlenu grupy OH, a powierzchnią atomu żelaza występuje silne oddziaływanie. Jest to prawdopodobnie spowodowane oddziaływaniem wolnej pary elektronowej tlenu z elektronami atomu żelaza na orbitalach 3d. Przy niskim poziomie pokrycia (0,25 ML), najbardziej uprzywilejowane centra aktywne stanowią podwójne pozycje mostkowe, a orientacja wiązania O-H jest prostopadła do powierzchni. Ponadto energia adsorpcji zmniejsza się wraz ze wzrostem ilości grup OH na powierzchni.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2A; 931-933
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Density functional theory based modeling of the corrosion on iron surfaces
Modelowanie korozji na powierzchni żelaza w oparciu o teorię funkcjonału gęstości
Autorzy:
Nunomura, N.
Sunada, S.
Powiązania:
https://bibliotekanauki.pl/articles/351628.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
density functional theory
aqueous corrosion
iron surface
water molecules
oxygen
teoria funkcjonału gęstości
korozja wodna
powierzchnia żelaza
cząsteczki wody
tlen
Opis:
In order to understand the first steps of the aqueous corrosion of iron, we have performed density functional theory (DFT) based calculations for water molecules and pre-covered oxygen on iron surface. The surface structure is modeled by iron atomic layer and vacuum region, and then oxygen atom and water molecules are displaced on the surface. Self consistent DFT calculations were performed using a numerical atomic orbital basis set and a norm-conserve pseudopotential method. According to our calculations, with increasing surface oxygen coverage, the iron surface is found to be not activated, which leads to a feeble adsorption of water molecules on iron surface. Our results show that the surface covered oxygen exerts an influence on the adsorption of water molecules on iron surface.
W celu zrozumienia początkowych etapów korozji żelaza w środowisku wodnym wykonaliśmy obliczenia dla cząsteczek wody i powierzchni żelaza pokrytej tlenem przy użyciu teorii funkcjonału gęstości (DFT). Model struktury powierzchni zawiera warstwę atomów żelaza i obszar próżni, a następnie atomy tlenu i cząsteczki wody rozmieszczane na powierzchni. Obliczenia DFT wykonano w zastosowaniem bazy orbitali atomowych i metody pseudopotencjału zachowania normy (norm-conserve). Zgodnie z wynikami naszych obliczeń, ze wzrostem pokrycia powierzchni przez tlen, powierzchnia żelaza nie jest aktywowana, co prowadzi do słabej adsorpcji cząsteczek wody na powierzchni żelaza. Nasze wyniki wskazują, ze powierzchnia pokryta tlenem wywiera wpływ na adsorpcje cząsteczek wody na powierzchni żelaza.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 2; 321-323
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of Steel Ball Samples, Investigated before and after Nitriding
Autorzy:
Fuks, H.
Kaczmarek, S. M.
Leniec, G.
Michalski, J.
Kucharska, B.
Wach, P.
Powiązania:
https://bibliotekanauki.pl/articles/355956.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
EPR-FMR
magnetization
iron
nitriding surface
Opis:
Group of steel balls with different chemical composition, diameters and nitriding treatment parameters were investigated with using magnetic resonance and magnetization methods. Emerging nitrided regions consists of diffusion and surface layer of iron nitrides. The thickness of the individual layers depends on the type of steel and process parameters. Resonance signal shape and position were successfully described in the ferromagnetic resonance regime expected for dense iron magnetic system. Influence of the sample size, thermal treatment and carbon content on the absorption signal has been analyzed. Significant magnetic anisotropy has been revealed, as well as non-usual increasing of the magnetization as a function of temperature. It suggests, that overall antiferromagnetic ordering, destroyed by thermal movement, lead to increasing of the ferromagnetic region.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1235-1242
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure and Properties Evaluation of Ductile Cast Iron Subjected to Hot Plastic Deformation and Ambient Temperature Compression
Autorzy:
Chaus, Alexander S.
Čaplovič, Ľubomír
Pokrovskii, Artur I.
Sobota, Robert
Powiązania:
https://bibliotekanauki.pl/articles/28032472.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
ductile iron
plastic deformation
microstructure
properties
fracture surface
Opis:
The as-cast microstructure of ductile cast iron (DI) was investigated using light microscopy (LM) and SEM techniques. Further the influence of hot plastic extrusion at 1000°C with plastic strain in the range of 20-60-80% on the transformation of the as-cast microstructure and on the mechanical properties was studied. Besides this, the microstructure of DI subjected to hot extrusion after the fracture of the corresponding samples induced by compression tests was thoroughly investigated. It was found that compression had a dramatic influence on a shear deformation and hence shear fracture of the compressed samples. It was shown that the shear fracture of the hot deformed ductile iron is accompanied by the occurrence of a narrow zone of severe plastic deformation. The fracture surfaces of the extruded samples subjected to the tensile tests and the compression tests were examined.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 2; 639--648
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of machining of EN-GJL-250 and EN-GJS-400 cast irons on tribological behavior
Autorzy:
Martinez, J.
Pereira, A.
Perez, J. A.
Mathia, T.
Powiązania:
https://bibliotekanauki.pl/articles/94140.pdf
Data publikacji:
2015
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
tribological behavior
grey cast iron
spheroidal graphite cast iron
friction
surface wear
Opis:
In transport and, particularly in the case of the present study, naval industries, one of the major objectives of research on wear and friction is focused principally on solid lubrication. In the following paper, the tribological behaviors of two well-known, different cast irons, lamellar grey iron (EN-GJL-250) and spheroidal graphite ductile iron (EN-GJS-400), are compared and the results are analyzed. For each material's family, the surfaces’ properties are characterized at different stages of the machining process. The particular influence of diverse feed rates in a turning facing is evaluated. Moreover, some tests of the laser cladding process, which contribute to the improvement of superficial properties, are carried out; therefore, the initial morphology before surface treatment is carefully characterized and evaluated in the context of subsequent adhesion qualification. The final goal of the study is to deliver feasible initial information concerning two similar cast irons that are traditionally used in the naval industry, which would be manufactured and employed in the future as dry lubricated bearings
Źródło:
Archives of Mechanical Technology and Materials; 2015, 35; 12-22
2450-9469
Pojawia się w:
Archives of Mechanical Technology and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Nickel on the Microstructure, Mechanical and Tribological Properties of Austempered Ductile Cast Iron for Steering Knuckle Applications
Autorzy:
Ramkumar, T.
Madhusudhanan, S.
Rajendran, I.
Powiązania:
https://bibliotekanauki.pl/articles/356391.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
austempered ductile iron
fatigue
impact
Ni
surface transition
wear
Opis:
The research article address, the mechanical properties such as fatigue, impact strength and tribological properties of Austempered ductile iron (ADI) has been investigated. The samples of ADI iron were austenitized at 927°C for 2 hrs and later it was under austempering process for 2 hrs at a temperature range of 240°C to 400°C. Experiments under axial loading has been carried out on three different compositions (without Ni(X), 0.22wt.%Ni(X1), 0.34wt.%Ni(X2). Fabricated test bars were converted in to as per ASTM standard samples for different tests. In order to study the influence of chunky nickel morphology studies on fatigue life and impact strength were carried out on a second set of specimens without any microstructural defect. Metallurgical analyses were performed on all the samples of heat treated samples (AF - Ausferrite, MB - Mixed bainite, M - Martensite, RA - Retained Austenite and N - Nodule) were found and compared. It was found that a mean content of 22% of chunky nickel in the microstructure (with respect to total Ni content) influence considerably the fatigue and impact strength properties of the cast iron. Moreover tribological properties of the specimens were also studied under dry sliding conditions at various sliding speed and load. The wear resistance and coefficient of friction were found to increase with increase in load and sliding speed.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 1; 15-25
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part I – Moulding technologies vs. zinc coating
Autorzy:
Szczęsny, A.
Kopyciński, D.
Guzik, E.
Powiązania:
https://bibliotekanauki.pl/articles/356585.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot-dip galvanizing
ductile iron
surface roughness
diffusion coefficient
Opis:
Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw) surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite) and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 385-390
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the Surface Layer of Iron Casting on the Growth of Protective Coating During Hot-Dip Galvanizing
Autorzy:
Kopyciński, D.
Guzik, E.
Szczęsny, A.
Powiązania:
https://bibliotekanauki.pl/articles/379701.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot-dip galvanizing
ductile iron
surface roughness
surface layer
cynkowanie
żeliwo sferoidalne
chropowatość powierzchni
Opis:
The paper presents the results of investigations of the growth of protective coating on the surface of ductile iron casting during the hot-dip galvanizing treatment. Ductile iron of the EN-GJS-600-3 grade was melted and two moulds made by different technologies were poured to obtain castings with different surface roughness parameters. After the determination of surface roughness, the hot-dip galvanizing treatment was carried out. Based on the results of investigations, the effect of casting surface roughness on the kinetics of the zinc coating growth was evaluated. It was found that surface roughness exerts an important effect on the thickness of produced zinc coating.
Źródło:
Archives of Foundry Engineering; 2016, 16, 1; 25-28
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part II – Technological formula and value of diffusion coefficient
Autorzy:
Kopyciński, D.
Guzik, E.
Szczęsny, A.
Powiązania:
https://bibliotekanauki.pl/articles/352224.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot-dip galvanizing
ductile iron
surface roughness
diffusion coefficient
Opis:
The completed research presented in the first part of the article has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing. On the basis of these data simulations were carried out to examine the behaviour of zinc diffusion coefficient D in the galvanized coating. The adopted model of zinc coating growth helped to explain the cases of excessive growth of the intermetallic phases in this type of coating. The paper analyzes covered the relationship between the roughness and phase composition of the top layer of product and the thickness and kinetics of zinc coating growth referred to individual sub-layers of the intermetallic phases.Roughness and phase composition in the surface layer of product were next related to the diffusion coefficient D examined in respective sublayers of the intermetallic phases.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 391-395
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on different behavior and mechanism of Ca(II) and Fe(III) adsorption on spodumene surface
Autorzy:
Yu, F.
Wang, Y.
Wang, J.
Xie, Z.
Powiązania:
https://bibliotekanauki.pl/articles/110230.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
spodumene surface
calcium ions
iron ions
adsorption mechanism
DFT calculation
Opis:
Behavior and mechanism of Ca2+ and Fe3+ adsorption on spodumene surface were investigated by micro flotation tests, zeta potential measurements, and density functional theory (DFT) calculation methods. The micro flotation tests showed that Ca2+ and Fe3+ activated the flotation of spodumene remarkably. However, the effect of Fe3+ was more significant than that of Ca2+. Additionally, Fe3+ significantly changed the zeta potential of spodumene while Ca2+ showed a little change. Meanwhile, the calculated adsorption energy of Fe3+ on spodumene surface was much greater than that of Ca2+ indicating that Fe3+ is more apt to be adsorbed on spodumene surface than Ca2+. The value of bond population in Ca-O illustrated that the bond of Ca-O consists of partial covalent proportion and some ionic component. On the contrary, the bond of Fe-O showed a relatively strong covalent property. The partial density of states (PDOS) of free Ca/Fe and the reacted O atom on spodumene (110) surface before and after the adsorption showed that Fe 3d orbital and O 2p orbital formed hybridization. The density of states (DOS) near the Fermi level of spodumene surface after adsorption with Fe3+ was much stronger than that with Ca2+.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 2; 535-550
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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