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1

Copper oxide–ferric oxide nanocomposite: Synthesis, characterization, and antibacterial and antifungal properties

Elnouby Mohamed, Nabil Marwa, Al-Askar Abdulaziz A., Kowalczewski Przemysław, Abdelkhalek Ahmed

Materials Science Poland

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2024

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Vol. 42, No. 3

100--110

EN

Recently, copper oxide–ferric oxide nanocomposites (CuO/Fe2O3-NCs) have gained popularity and are widely employed in various applications. However, their effectiveness against phytopathogens has not been studied yet. This study investigates the synthesis and characterization of CuO/Fe2O3-NCs using the hydrothermal technique. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FTIR) were used to characterize the produced nanocomposite (NC). EDX and TEM analyses revealed the presence of Cu, Fe, and O elements. The NC had a polygonal shape with sides around 12 nm, spherical CuO particles of 7–10 nm, and plate-likeFe2O3. XRD measurements confirmed the crystal and hexagonal structures of CuO and Fe2O3. The XRD patterns of CuO/Fe2O3 showed the characteristic peaks of (−111) and (004) reflections for CuO at 35.69° and 37.73°. The FTIR spectra showed characteristic lines at 525 and 567 cm−1 for the Cu–O bond and Fe–O stretching modes of Fe2O3, respectively. The antifungal activity of CuO/Fe2O3-NCs showed significant growth inhibition of Fusarium oxysporum, Rhizoctonia solani, and Botrytis cinerea by up to 71, 50, and 81%, respectively, at 100 µg/mL. At 50 µg/mL, the antibacterial test revealed inhibition zones of 12.33 mm for Pectobacterium carotovorum, 9.33 mm for Streptomyces scabies, 10.67 mm for Pectobacterium atrosepticum, and 14.67 mm for Ralstonia solanacearum. The results show that CuO/Fe2O3-NCs can efficiently suppress the growth of various fungal and bacterial strains, making them potential antimicrobial agents against phytopathogenic microorganisms.

2

Wpływ szybkości chłodzenia na mikrostrukturę oraz twardość brązu aluminiowo-niklowego stosowanego w separatorach łożysk tocznych

Łęczycki Krzysztof

Journal of KONBiN

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2024

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Vol. 54, iss. 4

99--110

PL

W publikacji przedstawiono wyniki badań wpływu szybkości chłodzenia na mikrostrukturę oraz twardość brązu aluminiowo-niklowego typu CuAl10Ni5Fe4. Próbki pobrano z separatora łożyska tocznego wymontowanego z silnika GTD-350. Próba polegała na wygrzaniu próbek w piecu nagrzanym do 1000°C przez 30 min oraz na chłodzeniu w trzech ośrodkach: w oleju silnikowym, na spokojnym powietrzu oraz razem z piecem. Obserwacje mikrostruktury przeprowadzono na mikroskopach świetlnych oraz transmisyjnym mikroskopie elektronowym. Twardość zmierzono metodą Vickersa. Przeprowadzone badania wskazują, że im większa szybkość chłodzenia tym większa twardość materiału. Jest to związane z dwoma czynnikami. Pierwszy to różnice w morfologii oraz typie ziaren osnowy materiału. Próbki wygrzewane i studzone z piecem oraz na powietrzu wykazywały obecność fazy α w postaci iglastej struktury Widmanstattena, przy czym w przypadku próbki studzonej na powietrzu rozmiar igieł był mniejszy. Natomiast studzenie w oleju doprowadziło do powstania struktury martenzytycznej. Drugim czynnikiem jest rozmiar wydzieleń – im większa szybkość studzenia, tym mniejszy jest maksymalny rozmiar wydzieleń.

3

On some Features of the Grain and Subgrain Size in a Cu-Cr-Zr Alloy After ECAP Processing and Aging

Abib Khadidja, Alili Baya, Baudin Thierry, Helbert Anne-Laure, Brisset Francois, Litynska-Dobrzynska Lidia, Zieba Paweł, Bradai Djamal

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 1

9--16

EN

A Cu-1Cr-0.1Zr alloy has been subjected to ECAP processing via route Bc and aging at 250-800°C. Electron BackScatter diffraction (EBSD), Transmission Electron Microscopy (TEM) and X-Ray Diffraction Line Profile Analysis (XRDLPA) techniques have been used to unveil some peculiarities of the grain and subgrain structure with a special emphasis on the comparison of the grain size estimated by the three techniques. For the alloy ECAP processed and aged up to 16 passes, the grain size (from EBSD, 0.2 < d < 5 μm), subgrain size (from TEM, d ~ 0.75 μm) and “apparent” average crystallite size (from XRDLPA, d < 0.25 μm) are manifestly different. The results were compared to the published data and analyzed based on the fundamental aspects of these techniques.

4

Rapidly solidified Al-Cu-Co quasicrystalline alloy: microstructure and catalytic properties

Zięba Amelia, Stan-Głowińska Katarzyna, Duraczyńska Dorota, Lityńska-Dobrzyńska Lidia

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 2

art. no. e127, 2024

EN

This study presents the characterisation and evaluation of the catalytic potential of an alloy with a composition referring to the quasicrystal from the Al-Cu-Co system. The material was synthesised through a melt-spinning process, providing rapid solidification conditions and a favourable material form of thin ribbons. Microstructural and chemical analyses were performed using scanning electron microscopy, X-ray diffraction and transmission electron microscopy methods. The obtained results confirmed the presence of a major phase which was a decagonal quasicrystal in the form of globular grains and additional crystalline phases occurring along the grain boundaries. The catalytic potential of the materials was explored using phenylacetylene hydrogenation. The catalyst, obtained by pulverising the ribbons, demonstrated catalytic activity with over 40% phenylacetylene conversion and selectivity exceeding 60% for styrene production under mild reaction conditions. The recovered catalyst displayed a stable phase composition, as confirmed by X-ray diffraction, and unchanged morphology, indicating the possibility of catalyst reuse for subsequent reaction cycles. The presented results provide insight into the experimental verification of the catalytic properties of the developed environmentally friendly catalysts.

5

Morphology and microstructure of Yb2O3 layer formed over aluminide coating produced by pack cementation of Haynes® 263 alloy

Morgiel Jerzy, Dudziak Tomasz, Rząd Ewa, Morgiel Krzysztof, Kateusz Filip

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 2

art. no. e59, 2024

EN

Intermetallic coatings from the Ni-Al system modified with rare earth elements (REE) additions are developed to protect the Ni-based superalloys against the increasingly demanding operating conditions, like those at ultra-supercritical (A-USC) power plants. The pack cementation process is generally limited to treatment of smaller parts, but simultaneously it allows to produce thick, well adhering and easily alloyed coatings. In this experiment, the Haynes® 263 alloy was subjected to pack cementation (PC) aluminizing process. The powder bed used in this experiment was prepared in two stages, i.e., first, the Al (8 wt.%), AlCl3 (4 wt.%), and Al2O3 (88 wt.%) powders were thoroughly mixed and only then, the Yb (1.5 wt.% of the all former) was added. The coating obtained through this process was investigated using scanning and transmission electron microscopy (SEM/TEM) methods. It helped to prove that the diffusive layer consisted mostly of Al14Cr3Ni2 ζ-phase, with significant amount of Al13(Co, Cr)4 and (Ni, Co, Cr)3Al4 larger precipitates as well as numerous smaller ones, composed of (Al, Ni, Co, Cr, Ti) or (Al, Ni, Co, Cr, Mo). The additive layer consisting of Al3Ni2 phase with up to 6 at. % Co and 2 at. % Cr was covered by a discontinuous layer of α-Al2O3 occasionally decorated with particles of the same phase. Only the very surface was found to be occupied by an amorphous Yb2O3 oxide, which formed a thin (~ 5 nm), but simultaneously a continuous layer. The latter finding is the first experimental documentation of the location of REE in the coating obtained through PC process using a powder bed modified with elements from that group.

6

The Influence of γ' Precipitates on the Structural Stability of FeNi-CoAlTa and FeNiCoAlTaB Single Crystals After Cyclic Superelastic Deformation

Wójcik Anna, Chulist Robert, Szewczyk Arkadiusz, Dutkiewicz Jan, Maziarz Wojciech

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

1157--1164

EN

Two single crystals with compositions Fe-Ni-Co-Al-Ta and Fe-Ni-Co-Al-Ta-B were selected and fabricated by Bridgman method. Subsequently, ingots were homogenized, oriented and subjected to a two-step heat treatment process in order to obtain fine and coherent γ' precipitates. Subsequently, superelastic cycling experiments were performed at 77 K. The next step included detailed microstructural characterization using transmission electron microscopy and high-energy synchrotron X-ray diffraction measurements together with Rietveld refinement. The results show that the number of fully reversible superelastic strains is very sensitive to the size of γ' precipitates. The smaller (3 nm) γ' precipitates ensured more superelastic response compared to material with larger γ' particles size (5 nm), in which the material did not receive its original shape after 10 cycles even after being heated.

7

TEM, HREM, L-TEM Studies of Fe-Based Soft Magnetic Melt-Spun Ribbons Subjected to Ultra-Rapid Annealing Process

Maziarz Wojciech, Kolano-Burian Aleksandra, Kowalczyk Maciej, Błyskun Piotr, Chulist Robert, Czaja Paweł, Szlezynger Maciej, Wójcik Anna

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

1165--1170

EN

In the present work, we performed the ultra-rapid annealing (URA) process for amorphous Fe78Ni8B14 melt-spun ribbons in order to obtain fine excellent microstructure assuring the best soft magnetic properties. Several microscopic methods mainly based on transmission electron microscopy (TEM) and Lorentz TEM (L-TEM) were applied for detailed studies of the microstructure and magnetic domains structure. The investigation revealed that the optimized parameters of the URA process (500°C/0.5-5 s) lead to outstanding soft magnetic properties. A mixture containing close to 50% amorphous phase and 50% α-Fe nanocrystals of size up to 30 nm has been already obtained after annealing for 3 s. These annealing conditions appear to be the most suitable in terms of microstructure providing the best magnetic properties.

8

Role of Nitrogen During Dry-Air Oxidation of TiAlNbCrSi Alloy Produced with Mould Casting (MC) and Electron Beam Melting (EBM)

Morgiel Jerzy, Dudziak Tomasz, Maj Łukasz, Kirchner A., Pomorska Małgorzata, Klöden B., Weissgärber T., Toboła Daniel

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

1183--1189

EN

The lack of room-temperature ductility of high-strength TiAl-based alloys called for complicated high temperature processing limiting their application areas. Introduction of additive manufacturing (AM) methods allowed to circumvent this disadvantage, but entailed microstructure refinement affecting, among the others, their oxidation resistance. The dry-air high temperature oxidation processing of TiAl-based alloys is relatively well covered for coarse grained materials, but to what extent the TiAl alloys are affected by the changes caused by the AM remains to be found out. Additionally, the role of nitrogen during these processes was to large extent omitted in previous works. Within the present experiment, the mould cast (MC) and the electron beam melted (EBM) Ti-48Al-2Nb-0.7Cr-0.3Si (at. %) RNT650 alloys were dry-air oxidized at 650°C for 1000 h. The TEM/EDS investigations allowed to confirm that the scale formed during such treatment consists of the layers occupied predominantly by TiO2+Al2O3/TiO2/Al2O3 sequence. Additionally, it was shown that N diffuses to the sub-scale and reacts with the substrate forming two distinct discontinuous sub-layers of α2-Ti3Al(N) and TiN. The scale over EBM was noticeably less porous and nitrogen penetration of the substrate was more extensive, while the MC showed higher susceptibility to local sub-scale oxidation.

9

Effect of Heat Treatment on Microstructure and Mechanical Properties of High-Carbon and High-Manganese Cast Steel Subjected to Bainitic Reaction

Garbień P., Kokosza A., Maj W., Rogal Łukasz, Chulist Robert, Janus K., Wójcik Anna, Żółkiewicz Z., Maziarz Wojciech

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 4

1667--1676

EN

The new cast steel with a chemical composition of Fe-(0.85-0.95)C-(1.50-1.60)Si-(2.40-2.60)Mn-(1.0-1.2)Al-(0.30-0.40)Mo-(0.10-0.15)V-(1.0-1.1)Ni (all in wt.%) was investigated in aspect of formation of the multiphase microstructure leading to high strength and ductility. Two types of heat treatment technologies were developed. The first one involves softening annealing at a temperature of 650°C for 4 hours, heating up to 950°C and holding for 2 hours, and then fast cooling down to 200°C and isothermally treated for 2 hours. The second one involves homogenizing annealing at 1100°C for 6 hours, then cooling with furnace down to 950°C and holding for 2 hours, then fast cooling down to 200°C and isothermally treated for 2 hours. A unique microstructure of cast steel consisting of martensite and retained austenite plates of various thicknesses and volume fractions was obtained. Additionally, nanometric transition carbides were noticed after the above-mentioned heat treatments. This microstructure ensures high hardness, strength and plasticity (Rm = 1426 MPa and A = 9.5%), respectively, due to the fact that TWIP/TRIP processes occur during deformation related to the high volume fraction of retained austenite, which the stacking fault energy is above 15 mJ/m-2 resulting from the chemical composition of the investigated cast steel.

10

Possibility of obtaining lanthanum doped nickel coatings from baths based on deep eutectic solvents

Niciejewska Anna, Tylus Włodzimierz, Marczewski Marek, Winiarska Katarzyna, Szczygieł Bogdan, Winiarski Juliusz

Ochrona przed Korozją

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2022

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nr 11

344--349

EN

Lanthanum-doped nickel coatings were obtained from the bath based on a deep eutectic solvent: choline chloride and propylene glycol, mixed in a molar ratio of 1 : 2, and 0.2 mol dm−3 NiCl2 ∙ 6H2O and 0.5 mol dm−3 LaCl2 ∙ xH2O. The morphology, topography and chemical composition were examined. The lanthanum content in the coating was determined to be 1.7 wt. % using the ICP-MS method. Lanthanum on the surface was mainly in the form of lanthanum carbonate. The obtained coating was exposed to a 7-day exposure in 0.05 mol dm−3 NaCl solution. The coating showed the highest corrosion resistance (Rp ~ 30 kΩ cm2) after 15 hours of exposure to the NaCl solution.

PL

Powłoki niklowe domieszkowane lantanem zostały otrzymane z kąpieli na bazie rozpuszczalnika eutektycznego chlorku choliny i glikolu propylenowego zmieszanych w proporcjach molowych 1 : 2 oraz 0,2 mol dm−3 NiCl2 ∙ 6H2O i 0,5 mol dm−3 LaCl2 ∙ xH2O. Zbadano morfologię, topografię oraz skład chemiczny. Zawartość lantanu w powłoce została określona na 1,7% mas. techniką ICP-MS. Na powierzchni powłoki lantan występował głównie w postaci węglanu lantanu. Otrzymana powłoka została poddana 7-dniowej ekspozycji w 0,05 mol dm−3 roztworze NaCl. Największą odporność na korozję powłoki stwierdzono po 15-godzinnej ekspozycji w roztworze NaCl.

11

Fabrication and amplified spontaneous emission behavior of FAPbBr3 perovskite quantum dots in solid polymer rods

Khan M. Naziruddin, Almohammedi Abdullah

Materials Science Poland

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2022

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Vol. 40, No. 1

84--100

EN

Formamidinium lead tribromide (FAPbBr3) perovskite quantum dot (PQ-Dot) solution was incorporated in a polymer sol, which was used to fabricate solid nanocomposite rods and disks. The solid nanocomposite samples were studied by different characterization techniques. The absorption, emission, and excitation spectra of the PQ-Dot in the solid rods/disks were quite significant as compared to the spectra of the PQ-Dot solution. Scanning electron microscopy (SEM) was used to inspect the structural morphology of the PQ-Dot in the solid environment. The PQ-Dot particles were evidently present in the solid matrix and were confirmed by the SEM images and energy dispersive X-ray spectroscopy (EDX) spectra. The size of the PQ-Dots was examined by transmission electron microscopy (TEM). The majority of the particles were about 3–8 nm in size. The spontaneous and stimulated emission profiles of the solid composite rods/disks were studied using pumping energy ranging from 2 μJ to 18 μJ from a high-power picosecond neodymium-doped yttrium aluminum garnet (Nd:YAG) tunable laser system. The observed emission signal was quite significant. The emission peak of the PQ-Dot solution had a slight change when it was included in the solid matrix. Amplified spontaneous emission (ASE) behavior was obtained from the PQ-Dot composite rod. The ASE peaks were quite steady at different levels of excitation energy. ASE was achieved at low threshold energy. The composite rod with ASE behavior indicates that it is a promising composite material that can be used to achieve lasing in the future. The ASE obtained from the composite rods/disks may improve to achieve lasing if a high concentration of PQ-Dot solution is used in the matrix.

12

The modern approach to manufacturing of carbon-rhenium nanocomposites

Dobrzańska-Danikiewicz A. D., Wolany W.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 115, nr 2

57--63

EN

Purpose: The aim of the paper is to present the high-temperature method of producing MWCNTs-Re nanocomposites, the selection of satisfactory production conditions and the presentation of the results of microscopic and spectroscopic studies of nanocomposites produced by this method. Design/methodology/approach: Two methods of manufacturing carbon-rhenium nanocomposites were tested: ineffective chemical synthesis and high-temperature reduction using H2, which was proven successful and allowed the production of nanocomposites with the expected properties. The received nanocomposites were investigated using Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM), as well as were subjected to spectroscopic examination. Findings: The article presents three steps of MWCNTs-Re nanocomposites fabrication using the high-temperature method, functionalization, impregnation and reduction. As part of own work, satisfactory conditions for producing those nanocomposites using a materials science and heuristic analysis were selected. Research limitations/implications: The proposed high-temperature method allows to join rhenium nanoparticles with MWCNTs permanently. It is reasonable to test in the future whether the method is also effective for other carbon nanomaterials and/or nanoparticles of other metals. Practical implications: MWCNTs-Re nanocomposites can be used as sensors of gases that are harmful to the environment. It was also confirmed that the MWCNTs-Re_4 nanocomposite has catalytic properties. Originality/value: The paper presents a modern approach to the manufacturing of MWCNTs-Re nanocomposites, which assumes the use of a high-temperature furnace to heat the material in a hydrogen atmosphere.

13

SEM/TEM Investigation of Degradation of Bi-Layer (Cr,Al)N/Cr2N3 Duplex Coatings Exposed to AlSi Alloy High Pressure Die Casting Cycles

Wilczek A., Morgiel Jerzy, Sypień Anna, Pomorska Małgorzata, Rogal Łukasz

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 4

1341--1348

EN

High pressure die casting (HDPC) allows to produce aluminum parts for car industry of complicated shapes in long series. Dies used in this process must be robust enough to withstand long term injection cycling with liquid aluminum alloys, as otherwise their defects are imprinted on the product making them unacceptable. It is expected that nitriding followed by coating deposition (duplex treatment) should protect them in best way and increase intervals between the cleaning/repairing operations. The present experiment covered investigations of the microstructure of the as nitride and deposited with CrAlN coating as well as its shape after foundry tests. The observations were performed with the scanning and transmission electron microscopy (SEM/TEM) method. They showed that the bottom part of this bi-layer is formed by roughly equi-axed Cr2N crystallites, while the upper one with the fine columnar (CrAl)N crystallites. This bi-layers were matched with a set of 7x nano-layers of CrN/(CrAl)N, while at the coating bottom a CrN buffer layer was placed. The foundry run for up to 19 500 cycles denuded most of coated area exposed to fast liquid flow (40 m/s) but left most of bottom part of the coating in the areas exposed to slower flow (7 m/s). The acquired data indicated that the main weakness of this coating was in its porosity present both at the columnar grain boundaries (upper layer) as well as at the bottom of droplets imbedded in it (both layers). They nucleate cracks propagating perpendicularly and the latter at an angle or even parallel to the substrate. The most crack resistant part of the coating turned-out the bottom layer built of roughly equiaxed fine Cr2N crystallites. Even application of this relatively simple duplex protection in the form of CrAlN coating deposited on the nitride substrate helped to extend the die run in the foundry by more than three times.

14

Modelowanie modułów termoelektrycznych w programie SPICE - przegląd

Posobkiewicz Krzysztof, Górecki Krzysztof

Przegląd Elektrotechniczny

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2021

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R. 97, nr 2

1--5

PL

W artykule przedstawiono wyniki badań dwóch literaturowych modeli modułów termoelektrycznych dedykowanych dla programu SPICE. Przedstawiono topologię oraz równania opisujące te modele. Pokazano także wyniki weryfikacji ich dokładności poprzez porównanie wyników pomiarów i obliczeń wykonanych w programie SPICE. Niezbędne wartości parametrów wyznaczono w oparciu o dane producenta.

EN

In the paper results of research of two published in literature SPICE models of thermoelectric modules have been presented. Topology and equations describing these models, as well as results of experimental verification of their accuracy, based on comparison of results of SPICE calculation and measurements have been discussed. Required models parameters values have been calculated using manufacturer data.

15

Synthesis, spectroscopic and thermogravimetric interpretations of UO2(II), ZrO(II), Zr(IV), VO(II) and V(V) ciprofloxacin antibiotic drug complexes

Albedair Lamia A.

Polish Journal of Chemical Technology

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2021

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Vol. 23, nr 1

45--52

EN

New five ciprofloxacin (CIP) complexes of dioxouranium(II), oxozirconium(II), zirconium(IV), oxovanadium(II) and vanadium(IV) in the proportion 1:2 have been prepared using CIP as a drug chelate with UO2(NO3)2. 6H2O, ZrOCl2. 8H2O, ZrC4, VOSO4. xH2O and V2O5 respectively. The CIP complexes have been characterized based on the elemental analysis, molar conductance, magnetic, (FTIR & 1HNMR) spectral and thermal studies. The molar conductance studies of the synthesized complexes in DMSO solvent with concentration of 10–3 M indicate their non-electrolytic properties. At room temperature, the magnetic moment measurements revealed a diamagnetic behavior for all CIP prepared complexes. The different formulas of the new complexes can be represented as [UO2(CIP)2(NO3)2] (I), [VO(CIP)2(SO4)(H2O)] (II), [V2(O)(O2)2(CIP)2] (III), [Zr(O)(CIP)2(Cl)2] (IV), and [Zr(CIP)2(Cl)4] (V). The thermal analysis data of the complexes indicates the absence of coordinated water molecules except for vanadyl(II) complex (II). The CIP chelate is a uni-dentate ligand coordinated to the mentioned metal ion through terminal piperazinyl nitrogen. The transmission electron microscopy (TEM) investigation confirms the nano-structured form of the complexes.

16

In situ thermal decomposition route: Preparation and characterization of nano nickel, cobalt, and copper oxides using an aromatic amine complexes as a low-cost simple precursor

Refat Moamen S., Mohamed Soha F., Altalhi Tariq A., Bakare Safyah B., Al-Hazmi Ghaferah H.

Polish Journal of Chemical Technology

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2021

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Vol. 23, nr 2

47--53

EN

The main interest now is the development of metallic or inorganic-organic compounds to prepare nanoparticle materials. The use of new compounds could be beneficial and open a new method for preparing nanomaterials to control the size, shape, and size of the nanocrystals. In this article, the thermal decomposition of [M2(o-tol)2(H2O)8]Cl4 (where o-tol is ortho-tolidine compound, M = Ni2+, Co2+, Cu2+) new precursor complex was discussed in solid-state conditions. The thermal decomposition route showed that the synthesized three complexes were easily decomposed into NiO, Co3O4 and CuO nanoparticles. This decomposition was performed at low temperatures (~600°C) in atmospheric air without using any expensive and toxic solvent or complicated equipment. The obtained product was identified by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). FT-IR, XRD and EDX analyses revealed that the NiO nanoparticles exhibit a face-centered-cubic lattice structure with a crystallite size of 9–12 nm. The formation of a highly pure spinel-type Co3O4 phase with cubic structure showed that the Co3O4 nanoparticles have a sphere-like morphology with an average size of 8–10 nm. The XRD patterns of the CuO confirmed that the monoclinic phase with the average diameter of the spherical nanoparticles was approximately 9–15 nm.

17

The qualitative-quantitative approach to microstructural characterization of nanostructured bainitic steels using electron microscopy methods

Królicka Aleksandra, Janik Aleksandra, Żak Andrzej, Radwański Krzysztof

Materials Science Poland

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2021

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Vol. 39, No. 2

188-199

EN

Both qualitative and quantitative analyses play a key role in the microstructural characterization of nanobainitic steels focused on their mechanical properties. This research demonstrates various methods of microstructure analysis using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) techniques, taking into account these two approaches. The structural constituents have been qualitatively characterized using TEM and selected area electron diffraction (SAED), together with quantitative analysis based on the misorientation angle (EBSD). Besides, quantitative measurement of austenite with both blocky and film-like morphologies has been carried out. Due to the scale of nanostructured bainite, it is also important to control the thickness of bainitic ferrite and film-like austenite; hence, a method for measuring their thickness is presented. Finally, the possibility of measuring the prior-austenite grain size by the EBSD method is also demonstrated and compared with the conventional grain boundary etching method. The presented methods of qualitative and quantitative analyses form a complementary procedure for the microstructural characterization of nanoscale bainitic steels.

18

Mechanisms of plastic deformation in light high-manganese steel of TRIPLEX type

Sozańska-Jędrasik Liwia, Borek Wojciech, Mazurkiewicz Janusz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e137412

EN

In this scientific publication, research results of two newly developed hot-rolled Fe-Mn-Al-C (X105) and Fe-Mn-Al-Nb-Ti-C (X98) types of steel were compared. These types of steel are characterized by an average density of 6.68 g/cm³, a value 15% lower compared to conventional structural steel. Hot rolling was carried out on a semi-industrial line to evaluate the effect of hot plastic deformation conditions with different cooling variants on the structure. The detailed analysis of phase composition as well as microstructure allows us to state that the investigated steel is characterized by an austenitic-ferritic structure with carbides precipitates. The results of the transmission electron microscopy (TEM) tests of both types of steel after hot rolling showed the occurrence of various deformation effects such as shear bands, micro bands, and lens twins in the microstructure. Based on the research undertaken with the use of transmission electron microscopy, it was found that the hardening mechanism of the X98 and X105 steel is deformation-induced plasticity by the formation of shear bands (SIP) and micro shear bands (MBIP).

19

Wire-feed assisted A-TIG welding of dissimilar steels

Sharma Pratishtha, Dwivedi Dheerendra Kumar

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 2

672--691

EN

This study investigates the activated flux-tungsten inert gas welding (A-TIG) welding of dissimilar P92 steel-304H ASS using ‘wire feed’ (patent pending) in terms of weld pool mixing behavior, microstructure and mechanical properties of the weld joint. ErNiCrMo-3 wire was fed during welding and three-wire feeding configurations were analyzed in view of filler wire melting and weld pool mixing behavior. The metal from filler wire is transferred into the weld pool in the form of ‘interrupted liquid bridge’ and ‘uninterrupted liquid bridge.’ The ‘uninterrupted liquid bridge’ melting resulted in homogeneous mixing of filler wire into the weld pool. The weld joint produced using the best wire feeding configuration was characterized and compared with the weld joint developed without wire feed. Microstructure alterations were realized with the use of wire feed. The weld zone with wire feed exhibited a fully austenitic structure, whereas; the completely martensitic structure was obtained using A-TIG welding without wire feed. The microstructural transformation led to the improvement of ductility and impact toughness of weld joint without substantial loss of tensile strength. The total elongation and impact toughness of the A-TIG weld joint with wire feed was 45.9% and (89 ± 2) J, respectively, which were significantly higher in contrast to the A-TIG weld joint without wire feed [total elongation: 37.4% and impact toughness: (30 ± 2) J].

20

Assessment of changes in microstructure and hardness of bearing steel for operation at a high temperature caused by short-term overheating

Łęczycki Krzysztof, Gronek Sebastian

Journal of KONBiN

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2020

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Vol. 50, iss. 4

89--110

EN

The paper presented research results of the impact of short-term overheating of samples collected from the outer bearing ring suitable for the operation at elevated temperature installed in the turbine engine on the microstructure and hardness of the material. The samples were annealed at the following temperatures: 500, 600, 700, 800, 900 and 1000°C; and then cooled in still air. Microstructure examinations were conducted under metallographic microscope and transmission electron microscope.

PL

W publikacji przedstawiono wyniki badań wpływu krótkotrwałego nagrzewania próbek pobranych z pierścienia zewnętrznego łożyska przeznaczonego do pracy w podwyższonej temperaturze z silnika turbinowego na mikrostrukturę oraz twardość jego materiału. Próbki wygrzewano w temperaturach: 500, 600, 700, 800, 900 i 1000°C, następnie studzono na spokojnym powietrzu. Badania mikrostruktury przeprowadzono, wykorzystując mikroskop metalograficzny oraz transmisyjny mikroskop elektronowy.